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Sample records for acidic media correlation

  1. Organic compounds as corrosion inhibitors for mild steel in acidic media: correlation between inhibition efficiency and chemical structure

    Elias, Elizandra C.S.; Chrisman, Erika C.A.N. [Universidade Federal do Rio de Janeiro (UFRJ), Rio de Janeiro, RJ (Brazil). Escola de Quimica

    2009-12-19

    The use of inhibitors for mild steels corrosion control which are in contact with aggressive environment is an accepted practice in acid treatment of oil-wells. Organic compounds have been studied to evaluate their corrosion inhibition potential. Film-forming corrosion inhibitors, commonly used to protect oil-field equipment, can be absorbed on the steel surface to give structurally ordered layers. Therefore, the electrons should act as an important role for this adsorption. Studies reveal that organic compounds show significant inhibition efficiency. For this purpose, their molecules should contain N, O and S heteroatoms in various functional groups, long hydrocarbon linear or branched radical and anion and cation active components. However, most of these compounds are not only expensive but also toxic to living beings. According to the 'Green Chemistry' rules, corrosion inhibitors based on organic compounds should be cheap, with low toxicity and have high inhibition efficiency. In this study, the effects of some organic compounds with different groups such as amide, ether, phenyldiamine, anime and aminophenol on the corrosion behavior of mild steel in acidic media have been investigated. The experimental data were obtained by gravimetric measurements. The results show that these compounds reveal a promising corrosion inhibition where phenyldiamine is the most efficient. The effect of molecular structure on the corrosion inhibition efficiency was investigated by semi-empirical quantum chemical calculations. The electronic properties such as highest occupied molecular orbital (HOMO), lowest unoccupied molecular orbital (LUMO) energy levels, and LUMO-HOMO energy gap orbital density were calculated. The relations between the inhibition efficiency and some quantum parameters are discussed and correlations are proposed. The highest values for the HOMO densities were found in the vicinity nitrogen atom, indicating that it is the most probable adsorption center

  2. Translation correlations in anisotropically scattering media

    Judkewitz, Benjamin; Horstmeyer, Roarke; Vellekoop, Ivo M.; Papadopoulos, Ioannis N.; Yang, Changhuei

    2015-08-01

    Controlling light propagation across scattering media by wavefront shaping holds great promise for a wide range of communications and imaging applications. But, finding the right shape for the wavefront is a challenge when the mapping between input and output scattered wavefronts (that is, the transmission matrix) is not known. Correlations in transmission matrices, especially the so-called memory effect, have been exploited to address this limitation. However, the traditional memory effect applies to thin scattering layers at a distance from the target, which precludes its use within thick scattering media, such as fog and biological tissue. Here, we theoretically predict and experimentally verify new transmission matrix correlations within thick anisotropically scattering media, with important implications for biomedical imaging and adaptive optics.

  3. Linear transport in correlated stochastic media

    The problem of linear transport in a stationary stochastic medium is examined in the context of stochastic geometry. Boolean models of stochastic media allow calculation of density correlations without use of Markovian assumptions. Most correlation functions are well represented by linear combinations of a few exponentials. Systems of integrodifferential equations are obtained either (a) by a perturbative treatment or (b) by truncation of the hierarchy of moments. The presence of an integral term (i.e., a nonlocal flux) can be avoided by the use of an approximate equivalence between the product of the transport Green function by an exponential with the transport Green function of a modified problem. Introduction of auxiliary unknowns gives rise to a system of coupled Boltzmann equations describing the ensemble average of the flux

  4. Social Media Correlates of Organizational Climate

    Smith, Daniel Crane

    2009-01-01

    This research (1) gathered data from a sample of employees on their social media practices and the social media policies of their employers and (2) investigated how blogging and other social media added to a model of organizational climate that promotes (a) knowledge sharing and cooperation, and (b) trust in peers and management. The research…

  5. Spatial photon correlations in multiple scattering media

    Smolka, Stephan; Muskens, O.; Lagendijk, A.;

    2010-01-01

    We present the first angle-resolved measurements of spatial photon correlations that are induced by multiple scattering of light. The correlation relates multiple scattered photons at different spatial positions and depends on incident photon fluctuations.......We present the first angle-resolved measurements of spatial photon correlations that are induced by multiple scattering of light. The correlation relates multiple scattered photons at different spatial positions and depends on incident photon fluctuations....

  6. Corrosion inhibition of mild steel in acidic media using newly synthesized heterocyclic organic molecules: Correlation between inhibition efficiency and chemical structure

    Ouici, H. B., E-mail: ouici.houari@yahoo.fr; Guendouzi, A., E-mail: guendouzzi@yahoo.fr [Departement of Chimistry, Faculty of Sciences, University of Saïda (Algeria); Benali, O. [Department of Biology, Faculty of Science, University of Saida (Algeria)

    2015-03-30

    The corrosion inhibition of mild steel in 5% HCl solutions by some new synthesized organic compounds namely 3-(2-methoxyphenyl) 5-mercapto-1. 2. 4-triazole (2-MMT), 3-(3-methoxyphenyl) 5-mercapto-1. 2. 4-triazole (3-MMT) and 3-(2-hydroxyphenyl) 5-mercapto-1. 2. 4-triazole (2-HMT) was investigated using weight loss and potentiostatic polarization techniques. These measurements reveal that the inhibition efficiency obtained by these compounds increased by increasing their concentration. The inhibition efficiency follows the order 2-MMT >3-MMT >2-HMT. Polarization studies show that these compounds are of the mixed type but dominantly act as a cathodic inhibitors for mild steel in 5% HCl solutions. These inhibitors function through adsorption following Langmuir isotherm. Activation energy and Gibbs free energy for adsorption of inhibitors are calculated. Molecular modeling has been conducted to correlate the corrosion inhibition properties with the calculated quantum chemical parameters.

  7. Velocity Correlations in Driven Two-Dimensional Granular Media

    Bizon, C.; Shattuck, M. D.; Swift, J. B.; Swinney, Harry L.

    1999-01-01

    Simulations of volumetrically forced granular media in two dimensions produce s tates with nearly homogeneous density. In these states, long-range velocity correlations with a characteristic vortex structure develop; given sufficient time, the correlations fill the entire simulated area. These velocity correlations reduce the rate and violence of collisions, so that pressure is smaller for driven inelastic particles than for undriven elastic particles in the same thermodynamic state. As the s...

  8. Dynamic Correlation in Wave Propagation in Random Media

    Chabanov, A. A.; Hu, B.; Genack, A. Z.

    2004-01-01

    We report time-resolved measurements of the statistics of pulsed transmission through quasi-one-dimensional dielectric media with static disorder. The normalized intensity correlation function with displacement and polarization rotation for an incident pulse of linewidth $\\sigma$ at delay time t is a function only of the field correlation function, which is identical to that found for steady-state excitation, and of $\\kappa_{\\sigma}(t)$, the residual degree of intensity correlation at points ...

  9. Spatio-temporal speckle correlations for imaging in turbid media

    Skipetrov, S.E.

    2001-01-01

    We discuss the far-field spatio-temporal cross-correlations of waves multiple-scattered in a turbid medium in which is embedded a hidden heterogeneous region (inclusion) characterized by a distinct scatterer dynamics (as compared to the rest of the medium). We show that the spatio-temporal correlation is affected by the inclusion which suggests a new method of imaging in turbid media. Our results allow qualitative interpretation in terms of diffraction theory: the cross-correlation of scatter...

  10. Air-breathing microfluidic fuel cells with a cylinder anode operating in acidic and alkaline media

    Highlights: • An air-breathing microfluidic fuel cell with a cylinder anode is proposed and tested. • The CO2 gas bubbles can be trapped between the anode and spacer. • The current production is well correlated with the dynamic behavior of CO2 bubbles. • CO2 bubbles improve the internal ohmic resistance by reducing the proton conduction. • The cell performance in the alkaline media is higher than that in the acidic media. - Abstract: An air-breathing microfluidic fuel cell with a cylinder anode is fabricated and characterized in the acidic and alkaline media. The dynamic behavior of CO2 bubbles is visualized in the acidic media, and its impact on current production is discussed. The effects of electrolyte concentration, reactant flow rate and channel length on the cell performance are also evaluated in the alkaline media. The results show that most of the CO2 bubbles are trapped between the anode and spacer in the acidic media, and the corresponding chronoamperometry curve is well correlated with the bubble movement. Further analysis indicates that the gas bubble improves the internal ohmic resistance by reducing proton conduction. In the alkaline media, the fuel cell yields a much higher performance than the acidic case, and fuel transfer limitation and cathode potential reversal occur at combined low flow rate and high current density. The cell performance is found to be predominated by ohmic resistance at flow rates over 200 μL min−1

  11. Large scale cross-drive correlation of digital media

    Bruaene, Joseph Van

    2016-01-01

    Approved for public release; distribution is unlimited Traditional digital forensic practices have focused on individual hard disk analysis. As the digital universe continues to grow, and cyber crimes become more prevalent, the ability to make large scale cross-drive correlations among a large corpus of digital media becomes increasingly important. We propose a methodology that builds on bulk-analysis techniques to avoid operating system- and file-system specific parsing. In addition, we a...

  12. The coulometric titration of acids and bases in dimethylsulfoxide media

    Bos, M.; IJpma, S.T.; Dahmen, E.A.M.F.

    1976-01-01

    The coulometric titration of 20–200 μeq of acids and bases in DMSO media is described. In the titration of bases, the electro-oxidation of hydrogen at a platinized platinum electrode is used as the source of protons. The conditions for 100 % current efficiency at this electrode are low current densi

  13. Electrochemical behavior of plutonium in nitric acid media

    The first step of the spent nuclear fuel reprocessing is a dissolution of actinides and fission products in hot nitric acid at high concentration. Among all these species, the knowledge of redox plutonium equilibria with discerning between their oxidation states is essential to understand and depended on many chemical conditions. Nevertheless, the knowledge of speciation in this media is a challenge especially for a better understanding of corrosion mechanism in the dissolution medium. Thus this paper proposes to determine the electrochemical behaviour of plutonium and especially the Pu(IV)/Pu(III), Pu(VI)/ Pu(V) and Pu(V)/Pu(IV) redox couple in nitric acid media and acquire thermodynamic and kinetic constants at higher temperatures than 25 deg C and higher nitric concentration than 1 mol L-1. (author)

  14. Understanding visual-auditory correlation from heterogeneous features for cross-media retrieval

    2008-01-01

    Cross-media retrieval is an interesting research topic, which seeks to remove the barriers among different modalities. To enable cross-media retrieval, it is needed to find the correlation measures between heterogeneous low-level features and to judge the semantic similarity. This paper presents a novel approach to learn cross-media correlation between visual features and auditory features for image-audio retrieval. A semi-supervised correlation preserving mapping (SSCPM) method is described to construct the isomorphic SSCPM subspace where canonical correlations between the original visual and auditory features are further preserved. Subspace optimization algorithm is proposed to improve the local image cluster and audio cluster quality in an interactive way. A unique relevance feedback strategy is developed to update the knowledge of cross-media correlation by learning from user behaviors, so retrieval performance is enhanced in a progressive manner. Experimental results show that the performance of our approach is effective.

  15. Correlating intravenous radiographic contrast media reactions with the allergic profile

    To determine the relevance of allergy as a predisposing factor in reactions to radiographic contrast media, the authors investigated the incidence of allergy among 100 randomly selected patients undergoing intravenous excretory urography and CT. The study population consisted of 50 reactors and 50 nonreactos to radiographic contrast media. All 100 subjects completed an allergy history, percutaneous allergy tests, and an in vitro specific IgE assay to common allergens. Thirty-four of 50 reactors had a positive allergy history, in contrast to 15 of 50 nonreactors (P < .001). Twenty-seven reactors had positive skin tests, in contrast to 12 of 50 nonreactors (P < .005). In vitro IgE assay results are pending. The results indicate that patients with positive histories or positive skin tests or both are at an increased risk for reactions to radiographic contrast media

  16. Experimental demonstration of spatial quantum correlations in multiple scattering media

    Smolka, Stephan; Huck, Alexander; Andersen, Ulrik Lund; Lagendijk, Ad; Lodahl, Peter

    We demonstrate that spatial quantum correlations are induced by multiple scattering of squeezed light. The correlation relates multiple scattered photons at different spatial positions, and is tunable by varying photon fluctuations of the illuminating beam.......We demonstrate that spatial quantum correlations are induced by multiple scattering of squeezed light. The correlation relates multiple scattered photons at different spatial positions, and is tunable by varying photon fluctuations of the illuminating beam....

  17. Infinite range correlations of intensity in random media

    A Retzker; B Shapiro

    2002-02-01

    We study a new type of long-range correlations for waves propagating in a random medium. These correlations originate from scattering events which take place close to a point source. The scattered waves propagate by diffusion to distant regions. In this way long range correlations, between any pair of distant points, are established.

  18. Chloroform extraction of ethyl xanthate complexes from sulphuric acid media

    The chloroform extraction of 30 elements (Fe, Co, Ni, Zn, Cd, Ge, Sn, V, As, Sb, Bi, Cu, Ag, Au, Mn, Re, Ga, In, Tl, Se, Te, Cr, Mo, U, Pt, Pd, Rh, Ir, Ru and Ce) from 0.1 to 8 M sulphuric acid in the presence of potassium ethyl xanthate has been studied. Pd(II), Bi, As(III), Sb(III), Se(IV) and Te(IV) are completely extracted and Au(III) is largely extracted over the range of acid concentration investigated. Fe(II), Tl(I), Rh(III) and Cr(VI) are only slightly extracted and Se(VI), Te(VI), Ru(III), Cr(III), Mn(II), Zn, Ce(IV), Ir(IV) and Ge(IV) are not extracted at all. Depending on the acid concentration, the remaining elements are all partly extracted. Results are compared with those obtained in an earlier study of the extraction of xanthate complexes from hydrochloric acid media. The processes involved in the formation of some xanthate complexes and potential analytical separations are discussed. (author)

  19. Impact of wettability correlations on multiphase flow through porous media

    de la Lama, Marta S.; Brinkmann, Martin

    2012-01-01

    In the last decades, significant progress has been made in understanding the multiphase displacement through porous media with homogeneous wettability and its relation to the pore geometry. However, the role of wettability at the scale of the pore remains still little understood. In the present study the displacement of immiscible fluids through a two-dimensional porous medium is simulated by means of a mesoscopic particle approach. The substrate is described as an assembly of non-overlapping...

  20. Simultaneous determination of amino acids and carbohydrates in culture media of Clostridium thermocellum by valve-switching ion chromatography.

    Fa, Yun; Yang, Haiyan; Ji, Chengshuai; Cui, He; Zhu, Xinshu; Du, Juan; Gao, Jun

    2013-10-10

    An improved method for the simultaneous determination of 20 amino acids and 7 carbohydrates using one-valve switching after injection, ion chromatography, and integrated pulsed amperometric detection is proposed. The resolution of the amino acids and carbohydrates in the cation trap column was investigated. In addition, parameters including flow liquid type, flow rate, concentration, and valve-switch timing were optimized. The method is time-saving, effective, and accurate for the simultaneous separation of amino acids and carbohydrates, with a mean correlation coefficient of >0.99 and repeatability of 0.5-4.6% for eight replicates. The method was successfully applied in the analysis of amino acids and carbohydrates in aseptic media and in extracellular culture media of three phenotypes of Clostridium thermocellum. PMID:24070489

  1. Correlation effects in focused transmission through disordered media

    Hsu, Chia Wei; Goetschy, Arthur; Cao, Hui; Stone, A Douglas

    2016-01-01

    By controlling the many degrees of freedom in the incident wavefront, one can manipulate wave propagation in complex structures. Such wavefront-shaping methods have been used extensively for controlling light transmitted into wavelength-scale regions (speckles), a property that is insensitive to correlations in the speckle pattern. Extending coherent control to larger regions should reveal correlation effects and is of great interest for several applications. Here we show with optical wavefront-shaping experiments that long-range correlations substantially increase the dynamic range of control over light transmitted onto larger target regions, when the number of targeted speckles, $M_2$, exceeds the dimensionless conductance $g$. Using a filtered random matrix ensemble appropriate for describing coherent diffusion in an open geometry, we show analytically that $M_2/g$ appears as the controlling parameter in universal scaling laws for several statistical properties of interest--predictions that we quantitative...

  2. Extraction of palladium(Ⅱ) with OTMSO from acidic media

    WU Songping; MENG Shuyuan; GU Guobang; ZHUANG Zhiqiang

    2004-01-01

    The extraction of palladium(Ⅱ) from acidic media with cyclic sulfoxide derivative-α-octyl-tetrahydrothiophene-l-oxide (OTMSO) was investigated. The extraction efficiency of palladination number was studied with slope method. The result indicates that coordination number is 2. FT-IR spectra were used to analyze the structure of complex and coordinated atom in complex. Pd is coordinated with both oxygen and sulfur atom in S=O group in OTMSO .The situation and intensity of peaks contributed by complex prepared from various acidity were different. The recovery of palladium(Ⅱ) with OTMSO from scrap containing palladium was discussed. After silver and bismuth were removed, the feed solution was extracted three times by 40% (volume fraction) OTMSO-kerosene. The loaded organic phase was scrubbed three times,and stripped three times by 2 mol@L-1 NH3·H2O solution.The total recovery of palladium was 99.8%,and the purity of palladium was 99.8%.

  3. NMR visualization of displacement correlations for flow in porous media.

    Khrapitchev, A A; Stapf, S; Callaghan, P T

    2002-11-01

    The temporal correlations of velocities for both water and a water-glycerol mixture flowing through a random packings of monodisperse spherical particles have been investigated using two-dimensional nuclear magnetic resonance methods. By combining various flow rates, fluid viscosities, and bead sizes, a wide range of flow parameters has been covered, the dimensionless Peclet number ranging from 100 to 100 000. The velocity exchange spectroscopy (VEXSY) technique has been employed to measure the correlation between velocities during two intervals separated from each other by a mixing time tau(m). This time is made both large and small compared with the time constant tau(c), required for a fluid element possessing the average flow velocity to cover a distance equal to the characteristic size in the system, the bead diameter. The two-dimensional conditional probability of displacement resulting from the VEXSY method reveals the existence of different "subensembles" of molecules, including a slow moving pool whose displacement is dominated by Brownian motion, an intermediate ensemble whose velocities change little over the mixing time, and a fast flowing ensemble which loses correlation due to mechanical dispersion. We find that that the approach to asymptotic dispersion, as tau(c)/tau(m) increases, depends strongly on the Peclet number, the deviation of the velocity autocorrelation function from a monoexponential Ornstein-Uhlenbeck process becoming more pronounced with increasing Peclet number. PMID:12513475

  4. Effect of a Previous Acid Adaptation of Zygosaccharomyces bailii on its Growth Kinetic in Acidic Media

    Alex Tchuenchieu

    2014-11-01

    Full Text Available The growth response of Zygosaccharomyces bailii acid adapted cells was assessed in acidified media. Yeast cells were first pre-cultured in nutrient broth adjusted with hydrochloric, citric and malic acid to pH 4; 4.5; 5; 5.5; 6 and 6.5. Moreover, they were also grown in two controls consisting of nutrient broth and nutrient broth supplemented with 1% of glucose both adjusted at pH 7. The variation of pH before and after the growth along with yeast concentration was measured. The cells pre-cultured in controls conditions and in the three conditions at pH 5 were then each inoculated in six BHI medium consisting of BHI adjusted with hydrochloric, citric and malic acid at pH 5.5 and 3.5. The growth was monitored by spectrophotometry and the yeast concentration after incubation was obtained by microscopy using a Thoma cell chamber. DMFit 2.1 was used to plot the growth curves and to estimate the growth parameters. All the pre-cultures and cultures were made at 37°C during 24 hours. During the pre-cultures, an important decrease of pH was noted in nutrient broth supplemented with glucose, moving from 7 to 3.81. In all the other pre-cultures, just a little variation was observed ranging from -0.57 to 0.50. Growth was observed in all the conditions, except at pH4. By growing the cells coming from the selected pre-cultures conditions in the different acidic BHI media, it appears that acid adaptation enhance the growth at pH 5.5 no matter the acid contains in the medium and the acid to which the cells were adapted. However, this acid adaptation was not sufficient to initiate growth at pH 3.5 after 24 hours of incubation at 37°C. Growth rate was significantly affected by the pH of the pre-culture medium and the acid present in the culture medium. Pre-culture with glucose supplementation was the only parameter studied affecting the latency.

  5. Pulse nebulization atomic absorption spectrometry after preconcentration from acidic media

    The possible advantages of the combination: chlorinated solvent extraction - pulse nebulization, abomic absorption spectrometry (AAS), as well as application of this method to multi-element determination of several important trace elements in biological samples is investigated. Hexamethyleneammonium hexamethylenedithiocarbamate (HMA-HMDTC) and ammonium pyrrolidinedithiocarbamate (APDC) as regents and CCl4, CHCl3, butylacetate (BuOAc) and methylisobutyl ketone (MIBK) as organic solvents are utilized. There is a tendency that CCl4 is the best solvent and MIBK - the worst. The study of extraction efficiency versus the ratio of aqueous-to-organic phase also shows the advantages of chlorinated solvents for extraction from acidic media. Better results are obtained with HMA-HMDTC as a reagent for Cu and Pb, whereas, for Cd extraction APDC gave a more efficient extraction. Chloroform shows a higher sensitivity enhancement factor, especially for volatile and/or chloride-forming elements. The extraction is successfully applied to determination of Cd, Cu and Pb in tissues of alfalfa, cabbage, carrots, onions, potatoes and wheat, as well as two standard reference materials. The results are in good agreement with the certified values

  6. Correlation between information diffusion and opinion evolution on social media

    Information diffusion and opinion evolution are often treated as two independent processes. Opinion models assume the topic reaches each agent and agents initially have their own ideas. In fact, the processes of information diffusion and opinion evolution often intertwine with each other. Whether the influence between these two processes plays a role in the system state is unclear. In this paper, we collected more than one million real data from a well-known social platform, and analysed large-scale user diffusion behaviour and opinion formation. We found that user inter-event time follows a two-scaling power-law distribution with two different power exponents. Public opinion stabilizes quickly and evolves toward the direction of convergence, but the consensus state is prevented by a few opponents. We propose a three-state opinion model accompanied by information diffusion. Agents form and exchange their opinions during information diffusion. Conversely, agents' opinions also influence their diffusion actions. Simulations show that the model with a correlation of the two processes produces similar statistical characteristics as empirical results. A fast epidemic process drives individual opinions to converge more obviously. Unlike previous epidemic models, the number of infected agents does not always increase with the update rate, but has a peak with an intermediate value of the rate. (paper)

  7. Photosynthesis and water relations in tomato plants cultivated long-term in media containing (+)-usnic acid.

    Latkowska, E; Lechowski, Z; Bialczyk, J; Pilarski, J

    2006-09-01

    The influence of (+)-usnic acid on rates of gas exchange (photosynthesis, respiration, and transpiration) in long-term cultivation of tomato plants was studied. The effect was dose-dependent. Plants grown in media containing the maximum concentration of (+)-usnic acid (30 muM) had photosynthetic and respiration rates reduced by 41% and 80%, respectively. The effect on photosynthesis rate may be the result of a multidirectional effect at various stages of this process, which at the highest usnic acid concentration underwent reduction: content of chlorophylls by 30%, carotenoids by 35%, and Hill reaction activity by 75%. Usnic acid also raises the susceptibility of chlorophyll to photodegradation. Under some conditions, transpiration was reduced by 2.1-fold in light and 3.7-fold in dark. This result was correlated with (1) an increase in the diffusive resistance of the stomata (3.1-fold in upper and 1.5-fold in lower surface of leaf), (2) a reduction of stomata density (by 60% on upper and 40% on lower surface), and (3) a 12.3-fold decrease in root hydraulic conductance. PMID:16902819

  8. Activation of Carbonyl-Containing Molecules with Solid Lewis Acids in Aqueous Media

    Román-Leshkov, Yuriy [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States). Chemical Engineering; Davis, Mark E. [California Inst. of Technology (CalTech), Pasadena, CA (United States). Chemical Engineering

    2011-09-28

    Current interest in reacting carbonyl-containing molecules in aqueous media is primarily due to the growing emphasis on conversion of biomass to fuels and chemicals. Recently, solid Lewis acids have been shown to perform catalytic reactions with carbonyl-containing molecules such as sugars in aqueous media. Here, catalysis mediated by Lewis acids is briefly discussed, Lewis acid solids that perform catalysis in aqueous media are then described, and the review is concluded with a few comments on the outlook for the future.

  9. Selectivity of colour reactions between elements and organic reagents in organo-aqueous acetic acid media

    Reasons, responsible for selectivity of photometric reactions in organo-aqueous acetic acid media, have been studied taking aluminium, gallium, and indium reactions as examples. Solution-and paper electrophoresis as well as distribution chromatography were used to examine the state of the elements in various media, including those for most selective determination of aluminium in the presence of gallium and indium. A high selectivity is due to the formation of an electrically neutral species of aluminium. And chloride complexes of gallium and indium in organo-aqueous acetic acid media. Coloured ternary complexes of aluminium with organic reagents and phosphoric acid are formed in the presence of the latter

  10. Modelling transport in media with correlated spatially variable physical and geochemical properties

    Preferential pathways for the release of radionuclides through heterogeneous media are of concern in performance assessment. Evidence of correlations exists between spatially variable fields of physical properties such as permeability and of geochemical properties such as sorption. Such correlations could lead to enhanced channelling of radionuclide transport. This possibility is studied, as the first stage of the MACRO-II joint experimental-modelling programme. MACRO-II continues the synthetic media approach to studying spatial variability used successfully in the first MACRO experiment. Batch and column experiments are being carried out to characterise the sorption behaviour of the ion-exchange beads. The results of the experiments will be used to fit and select the most appropriate mathematical model. The results confirm some of the initial concerns over the effect of correlations between physical and geochemical properties. The calculations have provided feedback on the experimental and calculational procedure proposed for the MACRO-II experiment. (R.P.)

  11. Intensity correlations in random media induced by refractive index tuning (RIT)

    Faez, Sanli; Lagendijk, Ad

    2009-01-01

    We introduce a new approach for measuring both the transport and the effective medium properties of light propagation in inhomogeneous media. These properties include the diffusion constant, the path length distribution, and the effective index of refraction. Our method utilizes the equivalence of frequency variation with a change in the index of refraction. A new correlation function that describes correlations in both frequency and index of refraction is introduced. Experimentally, we measure this correlation via spectrally resolved refractive index tuning (RIT), controlling the latter via changes in the ambient pressure. Our new generic measurement technique can be used to characterize a wide variety of materials, including photonic crystals, random photonic media, photonic meta-materials, and certain porous biological samples like bone and wood.

  12. Ultrasound evaluation of intima media thickness of carotid arteries in dialysis patients and correlation with proposed risk factors

    Damjanović Tatjana

    2003-01-01

    Full Text Available Atherosclerosis is significant risk factor for cardiovascular morbidity and mortality in dialysis patients. Aim of the study was ultrasound evaluation of intima media thickness on carotid arteries (as a marker of atherosclerosis, in dialysis patients and its correlation with proposed risk factors. Intima media thickness was measured in 45 dialysis patients with no signs of cardiovascular diseases (15 on peritoneal dialysis, group I,30 on hemodialysis, group II and 20 healthy controls. The mean carotid artery intima media thickness was significantly higher in dialysis patients than in control group. According to intima media thickness, dialysis patients were divided in group A (patient with intima media thickness less or equal 0,720 mm and group B (intima media thickness higher then 0,720mm. Intima media thickness in bout group was correlated with proposed risk factors. In group A there was not significant correlation of intima media thickness with risk factors. In group B significant correlation have been found between intima media thickness and LDL, VLDL cholesterol, body mass index and systolic, diastolic and mean blood pressure. Although atherosclerosis was not the only cause for cardiovascular morbidity and mortality, it has a dominant role in dialysis patients. Augmented intima media thickness could be early marker of atherosclerosis. The risk factors of great influence on intima media thickness are lipid disturbances, obesity and hypertension.

  13. Speciation of technetium in acidic media: effect of α radiations

    This project is part of the fundamental study of technetium speciation in highly acidic medium. The behaviour of technetium in HTFMS was carried out in the absence then in the presence of a irradiation. Given these two different conditions, spectrophotometric results of Tc(VII) reduction are similar. XAS analysis indicates the formation of a cyclic dimer of Tc(IV) complexed to triflate ligands and formulated asTc2O2(CF3SO3)4(H2O)4. This compound is linearized to Tc(IV)-O-Tc(IV) with the increase of HTFMS concentration. At high concentration of HTFMS +98% (11.15 M), the protonated species TcO3(OH)(H2O)2 which is formed in the absence of external ionizing radiations, is reduced to the V oxidation state under a irradiation. Structural characterization by EXAFS spectroscopy and DFT calculations suggests the formation of monomer species of Tc(V)-triflate complexes where [OTc(F3CSO3)2(H2O)2]+ and [OTc(F3CSO3)2(OH)2]- compounds were proposed. In concentrated H2SO4 (CH2SO4 ≥ 12 M), a-radiolysis experiments of Tc(VII) were performed in order to compare the radiolytic behaviour of Tc(VII) in both comparable media HTFMS and H2SO4. XANES studies show that radiolytic reduction of Tc(VII) leads to the formation of Tc(V)-Tc(VII) mixture in H2SO4 13 M and just Tc(V) in 18 M of H2SO4. The analysis of EXAFS spectra is consistent with the formation of [TcO(HSO4)3(H2O)2] and [TcO(HSO4)3(H2O)(OH)]- monomer complexes in H2SO4 13 M and [Tc(HSO4)3(SO4)(H2O)] and [Tc(HSO4)3(SO4)(OH)]- species at 18 M of H2SO4. (author)

  14. EFFECT OF GROWING MEDIA PROPERTIES AND ITS CORRELATION STUDY IN GERBERA PRODUCTION

    F. G. PANJ

    2014-03-01

    Full Text Available Effect of growing media properties and its correlation study in gerbera production was carried out under protected condition with different growing media combinations viz. soil, sand, FYM, vermi compost, coco peat and rice husk. Significant relationships were observed between different growing media parameters with flower quality and yield parameters of gerbera. To evaluate the apparent strength of the relationship and to explain the variations on dependent variable (crop yield multiple regression models were developed. In conclusion, it was found that the most important variables explaining the variations in the yield of gerbera were Water Holding Capacity (% (initial, pH (initial, Available N (% (initial, Available P (% (initial, pH (end, Available N (% (end and Available P (% (end.

  15. Two-phase flow in correlated pore-throat random porous media

    田巨平; 姚凯伦

    2002-01-01

    We have constructed a porous media model in which there are percolation clusters with varying percolation probability P and correlated site-bonds. Taking into account both the pore and the throat geometry, the viscous fingering (VF) in porous media has been investigated by using the standard over-relaxed Gauss-Seidel scheme. The simulation results show that the VF structure varies with the correlation parameter ε, the viscosity ratio M and the percolation probability P. The smaller the correlation parameter ε, the greater thedeviation of the normalized size distribution of the invaded throat Ninv(r) from the truncated Rayleigh distribution.For a larger viscosity ratio M,the VF pattern looks like a diffusion-limited-aggregation structure in percolation clusters. The fractal dimension D increases with the increase of the percolation probability P and the correlation parameter e. The velocity distribution f(α) of VF in percolation clusters is of a parabola-like curve. The tail of the distribution (large α) is longer for a larger correlation parameter ε. For a smaller ε, the distribution is very sharp. The sweep efficiency E decreases along with the decrease of the correlation parameter ε and the increase of the network size Lnz. E has a minimum as Lnz increases up to the maximum no matter what the values of P, M and ε. The E ~ Lnz curve has a frozen zone and an active zone. The geometry and the topology of the porous media have strong effects on the displacement processes and the structure of VF.

  16. Monte Carlo simulation of radioactive contaminant transport in fractured geologic media: Disorder and long-range correlations

    The geologic media near Yucca mountain site consist of fractured welded tuffs along with less fractured unwelded tuff. Numerical simulation of flow and transport in such media poses a number of challenging problems, due mainly to the heterogeneities and disorder in the media. In addition, because of different dominant transport mechanisms in different regions of the media, investigations need to be carried out at different time-scales. Time-marching will pose a considerable problem in analyzing such multi-scale transient problems. The authors develop a field-scale network model of fractures and study transport of radionuclides through geologic media as a function of disorder and correlated fracture-permeabilities

  17. Studies on photolysis of nitrosyl ruthenium complexes in nitric acid media

    The photolysis of nitrosyl ruthenium complexes in nitric acid media has been investigated in detail using low pressure mercury lamp (254 nm). The UV spectra of nitrosyl ruthenium complexes is also studied. The experimental results show that the photolysis of nitrosyl ruthenium in nitric acid media obeys pseudo-first order kinetics. The rate constant is affected by the concentration of nitric acid and has a maximum at 2 mol/L HNO3. In temperature range from 10 degree C to 40 degree C, the rate constant decreases with the increasing of the temperature

  18. Colour reactions of aluminium, titanium and other elements in organo-aqueous media containing acetic acid

    Colour reactions of titanium, aluminium, gallium, and indium in water-organic media, which also contain organic acids (acetic, formic, or their mixtures with acetone and propanol) are considered with the aim of using them in photometric methods for determining these elements. The reactants used were 2.7-bisazosubstituted components of chromotropic acid. It was established that the rate of development of colouring, the contrast and selectivity increase in water-organic media as compared with aqueous solutions. A favourable effect of acetic acid on the development of colour reactions is noted

  19. A transport phase diagram for pore-level correlated porous media

    Babaei, M.; Joekar-Niasar, V.

    2016-06-01

    Transport in porous media is often characterized by the advection-dispersion equation, with the dispersion coefficient as the most important parameter that links the hydrodynamics to the transport processes. Morphological properties of any porous medium, such as pore size distribution, network topology, and correlation length control transport. In this study we explore the impact of correlation length on transport regime using pore-network modelling. Earlier direct simulation studies of dispersion in carbonate and sandstone rocks showed larger dispersion compared to granular homogenous sandpacks. However, in these studies, isolation of the impact of correlation length on transport regime was not possible due to the fundamentally different pore morphologies and pore-size distributions. Against this limitation, we simulate advection-dispersion transport for a wide range of Péclet numbers in unstructured irregular networks with "different" correlation lengths but "identical" pore size distributions and pore morphologies. Our simulation results show an increase in the magnitudes of the estimated dispersion coefficients in correlated networks compared to uncorrelated ones in the advection-controlled regime. The range of the Péclet numbers which dictate mixed advection-diffusion regime considerably reduces in the correlated networks. The findings emphasize the critical role of correlation length which is depicted in a conceptual transport phase diagram and the importance of accounting for the micro-scale correlation lengths into predictive stochastic pore-scale modelling.

  20. Correlated mutations: a hallmark of phenotypic amino acid substitutions.

    Andreas Kowarsch

    Full Text Available Point mutations resulting in the substitution of a single amino acid can cause severe functional consequences, but can also be completely harmless. Understanding what determines the phenotypical impact is important both for planning targeted mutation experiments in the laboratory and for analyzing naturally occurring mutations found in patients. Common wisdom suggests using the extent of evolutionary conservation of a residue or a sequence motif as an indicator of its functional importance and thus vulnerability in case of mutation. In this work, we put forward the hypothesis that in addition to conservation, co-evolution of residues in a protein influences the likelihood of a residue to be functionally important and thus associated with disease. While the basic idea of a relation between co-evolution and functional sites has been explored before, we have conducted the first systematic and comprehensive analysis of point mutations causing disease in humans with respect to correlated mutations. We included 14,211 distinct positions with known disease-causing point mutations in 1,153 human proteins in our analysis. Our data show that (1 correlated positions are significantly more likely to be disease-associated than expected by chance, and that (2 this signal cannot be explained by conservation patterns of individual sequence positions. Although correlated residues have primarily been used to predict contact sites, our data are in agreement with previous observations that (3 many such correlations do not relate to physical contacts between amino acid residues. Access to our analysis results are provided at http://webclu.bio.wzw.tum.de/~pagel/supplements/correlated-positions/.

  1. Correlated mutations: a hallmark of phenotypic amino acid substitutions.

    Kowarsch, Andreas; Fuchs, Angelika; Frishman, Dmitrij; Pagel, Philipp

    2010-01-01

    Point mutations resulting in the substitution of a single amino acid can cause severe functional consequences, but can also be completely harmless. Understanding what determines the phenotypical impact is important both for planning targeted mutation experiments in the laboratory and for analyzing naturally occurring mutations found in patients. Common wisdom suggests using the extent of evolutionary conservation of a residue or a sequence motif as an indicator of its functional importance and thus vulnerability in case of mutation. In this work, we put forward the hypothesis that in addition to conservation, co-evolution of residues in a protein influences the likelihood of a residue to be functionally important and thus associated with disease. While the basic idea of a relation between co-evolution and functional sites has been explored before, we have conducted the first systematic and comprehensive analysis of point mutations causing disease in humans with respect to correlated mutations. We included 14,211 distinct positions with known disease-causing point mutations in 1,153 human proteins in our analysis. Our data show that (1) correlated positions are significantly more likely to be disease-associated than expected by chance, and that (2) this signal cannot be explained by conservation patterns of individual sequence positions. Although correlated residues have primarily been used to predict contact sites, our data are in agreement with previous observations that (3) many such correlations do not relate to physical contacts between amino acid residues. Access to our analysis results are provided at http://webclu.bio.wzw.tum.de/~pagel/supplements/correlated-positions/. PMID:20862353

  2. Humic acid transport in saturated porous media:Influence of flow velocity and influent concentration

    Xiaorong Wei; Mingan Shao; Lina Du; Robert Horton

    2014-01-01

    Understanding the transport of humic acids (HAs) in porous media can provide important and practical evidence needed for accurate prediction of organic/inorganic contaminant transport in different environmental media and interfaces.A series of column transport experiments was conducted to evaluate the transport of HA in different porous media at different flow velocities and influent HA concentrations.Low flow velocity and influent concentration were found to favor the adsorption and deposition of HA onto sand grains packed into columns and to give higher equilibrium distribution coefficients and deposition rate coefficients,which resulted in an increased fraction of HA being retained in columns.Consequently,retardation factors were increased and the transport of HA through the columns was delayed.These results suggest that the transport of HA in porous media is primarily controlled by the attachment of HA to the solid matrix.Accordingly,this attachment should be considered in studies of HA behavior in porous media.

  3. The Role of the Media in Body Image Concerns among Women: A Meta-Analysis of Experimental and Correlational Studies

    Grabe, Shelly; Ward, L. Monique; Hyde, Janet Shibley

    2008-01-01

    Research suggests that exposure to mass media depicting the thin-ideal body may be linked to body image disturbance in women. This meta-analysis examined experimental and correlational studies testing the links between media exposure to women's body dissatisfaction, internalization of the thin ideal, and eating behaviors and beliefs with a sample…

  4. Multiple scattering of polarized light in disordered media exhibiting short-range structural correlations

    Vynck, Kevin; Carminati, Rémi

    2016-01-01

    We develop a model based on a multiple scattering theory to describe the diffusion of polarized light in disordered media exhibiting short-range structural correlations. Starting from exact expressions of the average field and the field spatial correlation function, we derive a radiative transfer equation for the polarization-resolved specific intensity that is valid for weak disorder and we solve it analytically in the diffusion limit. A decomposition of the specific intensity in terms of polarization eigenmodes reveals how structural correlations, represented via the standard anisotropic scattering parameter $g$, affect the diffusion of polarized light. More specifically, we find that propagation through each polarization eigenchannel is described by its own transport mean free path that depends on $g$ in a specific and non-trivial way.

  5. Imaging in scattering media using correlation image sensors and sparse convolutional coding.

    Heide, Felix; Xiao, Lei; Kolb, Andreas; Hullin, Matthias B; Heidrich, Wolfgang

    2014-10-20

    Correlation image sensors have recently become popular low-cost devices for time-of-flight, or range cameras. They usually operate under the assumption of a single light path contributing to each pixel. We show that a more thorough analysis of the sensor data from correlation sensors can be used can be used to analyze the light transport in much more complex environments, including applications for imaging through scattering and turbid media. The key of our method is a new convolutional sparse coding approach for recovering transient (light-in-flight) images from correlation image sensors. This approach is enabled by an analysis of sparsity in complex transient images, and the derivation of a new physically-motivated model for transient images with drastically improved sparsity. PMID:25401666

  6. Imaging in scattering media using correlation image sensors and sparse convolutional coding

    Heide, Felix

    2014-10-17

    Correlation image sensors have recently become popular low-cost devices for time-of-flight, or range cameras. They usually operate under the assumption of a single light path contributing to each pixel. We show that a more thorough analysis of the sensor data from correlation sensors can be used can be used to analyze the light transport in much more complex environments, including applications for imaging through scattering and turbid media. The key of our method is a new convolutional sparse coding approach for recovering transient (light-in-flight) images from correlation image sensors. This approach is enabled by an analysis of sparsity in complex transient images, and the derivation of a new physically-motivated model for transient images with drastically improved sparsity.

  7. Individual variation and intraclass correlation in arachidonic acid and eicosapentaenoic acid in chicken muscle

    Olesen Ingrid

    2010-04-01

    Full Text Available Abstract Chicken meat with reduced concentration of arachidonic acid (AA and reduced ratio between omega-6 and omega-3 fatty acids has potential health benefits because a reduction in AA intake dampens prostanoid signaling, and the proportion between omega-6 and omega-3 fatty acids is too high in our diet. Analyses for fatty acid determination are expensive, and finding the optimal number of analyses to give reliable results is a challenge. The objective of the present study was i to analyse the intraclass correlation of different fatty acids in five meat samples, of one gram each, within the same chicken thigh, and ii to study individual variations in the concentrations of a range of fatty acids and the ratio between omega-6 and omega-3 fatty acid concentrations among fifteen chickens. Fifteen newly hatched broilers were fed a wheat-based diet containing 4% rapeseed oil and 1% linseed oil for three weeks. Five muscle samples from the mid location of the thigh of each chicken were analysed for fatty acid composition. The intraclass correlation (sample correlation within the same animal was 0.85-0.98 for the ratios of total omega-6 to total omega-3 fatty acids and of AA to eicosapentaenoic acid (EPA. This indicates that when studying these fatty acid ratios, one sample of one gram per animal is sufficient. However, due to the high individual variation between chicken for these ratios, a relatively high number of animals (minimum 15 are required to obtain a sufficiently high power to reveal significant effects of experimental factors (e.g. feeding regimes. The present experiment resulted in meat with a favorable concentration ratio between omega-6 and omega-3 fatty acids. The AA concentration varied from 1.5 to 2.8 g/100 g total fatty acids in thigh muscle in the fifteen broilers, and the ratio between AA and EPA concentrations ranged from 2.3 to 3.9. These differences among the birds may be due to genetic variance that can be exploited by

  8. Iridium-based double perovskites for efficient water oxidation in acid media

    Diaz-Morales, Oscar; Raaijman, Stefan; Kortlever, Ruud; Kooyman, Patricia J.; Wezendonk, Tim; Gascon, Jorge; Fu, W. T.; Koper, Marc T. M.

    2016-08-01

    The development of active, cost-effective and stable oxygen-evolving catalysts is one of the major challenges for solar-to-fuel conversion towards sustainable energy generation. Iridium oxide exhibits the best available compromise between catalytic activity and stability in acid media, but it is prohibitively expensive for large-scale applications. Therefore, preparing oxygen-evolving catalysts with lower amounts of the scarce but active and stable iridium is an attractive avenue to overcome this economical constraint. Here we report on a class of oxygen-evolving catalysts based on iridium double perovskites which contain 32 wt% less iridium than IrO2 and yet exhibit a more than threefold higher activity in acid media. According to recently suggested benchmarking criteria, the iridium double perovskites are the most active catalysts for oxygen evolution in acid media reported until now, to the best of our knowledge, and exhibit similar stability to IrO2.

  9. Correlation between histomorphometric changes and the type of aerobic bacteria isolated in chronic suppurative otitis media

    Živković-Marinkov Emilija

    2011-01-01

    Full Text Available Background/Aim. Bacterial flora is a very important factor in pathogenesis of chronic suppurative otitis media (CSOM and significantly influences the type and intensity of osteolytic process. There are few histomorphometric investigations of middle ear mucosa in chronic otitis. The aim of this study was to identify aerobic bacteria responsible for chronic suppurative otitis media as well as their association with histomorphometric changes of middle ear mucosa. Methods. A prospective study that comprised 153 patients treated in the Clinc for Ear, Thorat and Nose Diseases, Niš, was conducted. Bacteriologic analysis of diseased ear secretion was carried out in all patients. Intraoperatively removed granulation tissue was used for histomorphometry. The analysed parameters were: the number of inflammatory cells, as well as vascularization and vasodilatation. Results. The most frequently isolated aerobic bacteria from chronic suppurative otitis media were Staphylococcus aureus (29.02%, Pseudomonas aeruginosa (29.02% and Proteus spp. (21.76%. There was no correlation between the type of pathologic process and the type of bacteria.The number of inflammatory cells in the granulation tissue in pure cultures of Staphylococcus aureus was 1,597.33 ± 549.45 and in Pseudomonas auriginosa cultures was 2,639 ± 648. Conclusion. This study showed that there is a statistically significant correlation between the number of inflammatory cells in the granulation tissue and the type of aerobic bacteria we isolated. The intensity of the infection in chronic suppurative otitis media depends on the type of the isolated bacteria, which emphasizes the importance of adequate preoperative antimicrobial therapy.

  10. Effects of varying media, temperature, and growth rates on the intracellular concentrations of yeast amino acids.

    Martínez-Force, E; Benítez, T

    1995-01-01

    Variations of the yeast free amino acid pool under different culture conditions were studied in two Saccharomyces strains, the laboratory haploid strain S288C and the industrial fermentative yeast IFI256. The internal amino acid pool of both strains was measured when grown in laboratory (minimal and complete) versus semiindustrial (molasses with or without added biotin and/or diammonium phosphate) media, in fermentable (glucose, fructose, sucrose) versus respirable (glycerol) carbon sources, in different temperatures (22, 30, and 37 degrees C), pHs (2.0-4.75), and growth rates (0.018-0.24 h-1) in continuous culture, and at different phases of the growth curve in batch culture (lag, exponential, early and late stationary). Results indicated that environmental conditions, particularly the presence of amino acids in the media, enormously influenced the intracellular amino acid concentration. Higher values were detected in molasses than in laboratory media and in fermentable carbon sources (glucose, fructose, sucrose) than in glycerol. Variations in the amino acid pool along the growth curve were greater at 37 degrees C than at other temperatures; in all cases, the highest values were measured at the beginning of the exponential phase. In continuous culture and at different growth rates, intracellular free amino acid concentrations increased by 3-10-fold when the growth rate was lower than 0.05 h-1, representing 20-35% of the total (free plus protein) amino acid content and indicating that amino acid yield was a partly growth-linked parameter. PMID:7654310

  11. Aqueous citric acid as green reaction media for the synthesis of octahydroxanthenes

    Camilo A. Navarro D.

    2013-08-01

    Full Text Available A simple, convenient and environmentally friendly one-pot procedure for the synthesis of 1,8-dioxo-octahydroxanthenes by the reaction of dimedone and aromatic aldehydes in aqueous citric acid is described. In this green synthetic protocol promoted by the reaction media, the use of any other catalysts and hazardous organic solvents are avoided, making the work up procedure greener and easier. The isolation of the products, obtained in good yields, is readily performed by filtration and crystallization from ethanol when required and the aqueous acidic media can be easily recycled and reused several times without significant loss of catalytic activity.

  12. CORRELATES OF VARIOUS PRESENTATION MODES OF ACUTE OTITIS MEDIA IN SAUDI CHILDREN

    Al-Quaiz, Al-Joharaah M.

    2001-01-01

    Purpose: To describe correlates of various modes of presentation and identify some surrogates of poor outcome of children less than 5 years with Acute Otitis Media (AOM). Patients and Methods: This is a cross-sectional survey conducted at 11 primary health care centers in Riyadh city over 3 month period. A total of 140 children, each less than 5 years of age and presenting with a new episode of AOM were enrolled. Twenty-eight family physicians participated in the study. Each physician made th...

  13. Corrosion res ance of stainless steels in media of nitric-acid decomposition of apatite

    Presented are results of investigation of corrosion resistance of stainless steels 06KhN28MDT, 08Kh21N6M2T, 08Kh22N5T and Kh18N10T in media initiating composition of pulp liquid phase of nitric acid decompositon of apatite (phosphoric acid, hydrofluoric acid and fluosilicic acid). Principle application possibility of economically-alloyed as to nickel the 08Kh21N62MT steels for the apparatus equipment of the process instead of highly alloyed 06KhN28MDT steel is established

  14. The removal of uranium from acidic media using ion exchange and/or extraction chromatography

    The separation and purification of uranium from either nitric acid or hydrochloric acid media can be accomplished by using either solvent extraction or ion-exchange. Over the past two years at Los Alamos, emerging programs are focused on recapturing the expertise required to do limited, small-quantity processing of enriched uranium. During this period of time, we have been investigating ion-addition, waste stream polishing is associated with this effort in order to achieve more complete removal of uranium prior to recycle of the acid. Extraction chromatography has been demonstrated to further polish the uranium from both nitric and hydrochloric acid media thus allowing for a more complete recovery of the actinide material and creation of less waste during the processing steps

  15. The removal of uranium from acidic media using ion exchange and/or extraction chromatography

    FitzPatrick, J.R.; Schake, B.S.; Murphy, J.; Holmes, K; West, M.H.

    1996-06-01

    The separation and purification of uranium from either nitric acid or hydrochloric acid media can be accomplished by using either solvent extraction or ion-exchange. Over the past two years at Los Alamos, emerging programs are focused on recapturing the expertise required to do limited, small-quantity processing of enriched uranium. During this period of time, we have been investigating ion-addition, waste stream polishing is associated with this effort in order to achieve more complete removal of uranium prior to recycle of the acid. Extraction chromatography has been demonstrated to further polish the uranium from both nitric and hydrochloric acid media thus allowing for a more complete recovery of the actinide material and creation of less waste during the processing steps.

  16. Extraction of gold, palladium, and platinum from acidic media with cyclic sulfoxide derivative

    Songping Wu; Guobang Gu

    2007-01-01

    The extraction of gold (Ⅲ), palladium (Ⅱ), and platinum (Ⅳ) from the acidic media with the cyclic sulfoxide derivative of a-dodecyl-tetrahydrothiophene 1-oxide (dtmso) was investigated. Gold (Ⅲ), palladium (Ⅱ), and platinum (Ⅳ) could be separated from the acidic media with suitable sulfoxide concentration and acidity. The extraction reaction of gold (Ⅲ), palladium (Ⅱ) or platinum (Ⅳ) is exothermic when dtmso is used as an extracting reagent. The coordination number was studied by the slope method. The results indicate that, in high acidity, the dtmso coordination number for extracting gold (Ⅲ) or palladium (Ⅱ) is 3, and that for platinum (Ⅳ) is 2. UV and FT-IR spectra were used to analyze the structure of the complex. Gold (Ⅲ) is coordinated with the oxygen atom in S=O group in dtmso, and palladium (Ⅱ) or platinum (Ⅳ) is coordinated with the sulfur atom in S=O group in dtmso.

  17. Probability distributions for directed polymers in random media with correlated noise.

    Chu, Sherry; Kardar, Mehran

    2016-07-01

    The probability distribution for the free energy of directed polymers in random media (DPRM) with uncorrelated noise in d=1+1 dimensions satisfies the Tracy-Widom distribution. We inquire if and how this universal distribution is modified in the presence of spatially correlated noise. The width of the distribution scales as the DPRM length to an exponent β, in good (but not full) agreement with previous renormalization group and numerical results. The scaled probability is well described by the Tracy-Widom form for uncorrelated noise, but becomes symmetric with increasing correlation exponent. We thus find a class of distributions that continuously interpolates between Tracy-Widom and Gaussian forms. PMID:27575059

  18. The shape of invasion percolation clusters in random and correlated media

    The shape of two-dimensional invasion percolation clusters are studied numerically for both non-trapping (NTIP) and trapping (TIP) invasion percolation processes. Two different anisotropy quantifiers, the anisotropy parameter and the asphericity, are used for probing the degree of anisotropy of clusters. We observe that, in spite of the difference in scaling properties of NTIP and TIP, there is no difference in the values of anisotropy quantifiers of these processes. Furthermore, we find that, in completely random media, the invasion percolation clusters are on average slightly less isotropic than standard percolation clusters. Introducing isotropic long-range correlations into the media reduces the isotropy of the invasion percolation clusters. The effect is more pronounced for the case of persisting long-range correlations. The implication of boundary conditions on the shape of clusters is another subject of interest. Compared to the case of free boundary conditions, IP clusters of conventional rectangular geometry turn out to be more isotropic. Moreover, we see that in conventional rectangular geometry the NTIP clusters are more isotropic than the TIP clusters

  19. Aerobic growth of campylobacter in media supplemented with a-ketoglutaric, lactic, and/or fumaric acids

    A study was conducted to examine the ability of Campylobacter spp. to grow aerobically in media supplemented with selected organic acids. Basal broth media composed of tryptose, yeast extract, and a mineral-vitamin solution was supplemented with a-ketoglutaric, lactic, and/or fumaric acids. The fina...

  20. Correlation Between the Intima-Media Thickness of the Proximal and Distal Common Carotids

    Increased IMT (intima-media thickness) in carotids is used as an early atherosclerosis marker and to evaluate the risk of cardiovascular problems. Ultrasound is used in the evaluation because it is accessible and low cost. Measurements for different carotid regions are described. To compare the proximal and distal region IMTs for the bilateral common carotid and guide its use in clinical practice. The IMT was measured in the proximal and distal common carotid arteries of 798 individuals (35-74 years old) of both genders using high-resolution ultrasound. Pearson's correlation coefficient was used to establish associations. The analyses were initially performed for the entire sample as well as subgroups with IMT <0.90 mm (49% of the sample) and ≥0.90 mm for at least one measurement site. The statistical significance was p < 0.05. The correlations investigated were significant. In the group with an IMT <0.90 mm, the correlations were between 0.44 and 0.62. In the subgroup with an IMT ≥0.90 mm, the correlations were significantly reduced to between 0.20 and 0.40. The data suggest that the IMT is more uniform along the carotid during early development and tends develop focally as it progresses. Therefore, in clinical evaluations of patients, the common carotid length should be investigated bilaterally to better use the available software and discern the IMT

  1. Angle dependence of the frequency correlation in random photonic media: Diffusive regime and its breakdown near localization

    Muskens, O.L.; Beek, van der T.; Lagendijk, A.

    2011-01-01

    The frequency correlations of light in complex photonic media are of interest as a tool for characterizing the dynamical aspects of light diffusion. We demonstrate here that the frequency correlation shows a pronounced angle dependence both in transmission and in reflection geometries. Using a broad

  2. Radiation propagation in random media: From positive to negative correlations in high-frequency fluctuations

    We survey research on radiation propagation or ballistic particle motion through media with randomly variable material density, and we investigate the topic with an emphasis on very high spatial frequencies. Our new results are based on a specific variability model consisting of a zero-mean Gaussian scaling noise riding on a constant value that is large enough with respect to the amplitude of the noise to yield overwhelmingly non-negative density. We first generalize known results about sub-exponential transmission from regular functions, which are almost everywhere continuous, to merely 'measurable' ones, which are almost everywhere discontinuous (akin to statistically stationary noises), with positively correlated fluctuations. We then use the generalized measure-theoretic formulation to address negatively correlated stochastic media without leaving the framework of conventional (continuum-limit) transport theory. We thus resolve a controversy about recent claims that only discrete-point process approaches can accommodate negative correlations, i.e., anti-clustering of the material particles. We obtain in this case the predicted super-exponential behavior, but it is rather weak. Physically, and much like the alternative discrete-point process approach, the new model applies most naturally to scales commensurate with the inter-particle distance in the material, i.e., when the notion of particle density breaks down due to Poissonian-or maybe not-so-Poissonian-number-count fluctuations occur in the sample volume. At the same time, the noisy structure must prevail up to scales commensurate with the mean-free-path to be of practical significance. Possible applications are discussed.

  3. Radiation transport through random media represented as measurable functions: Positive versus negative spatial correlations

    We investigate particle transport through media with randomly variable material properties with a special emphasis on very high spatial frequencies. In multi-dimensional transport theory, particularly in computational studies, collision coefficients are assumed to be 'functions' in the conventional sense of the word: they have specific values at every point in the medium. This assumption actually constrains spatial variability in the high-frequency range in a manner that is not a mathematical necessity and relaxing it opens the door to interesting transport physics. From the standpoint of the integral transport equation, coefficient variations in space can indeed be represented as 'measures,' i.e., mathematical constructs that only make numerical sense under an integral (in the sense of Lebesgue). The new results are based on a variability model consisting of a zero-mean Gaussian scaling noise riding on a constant value large enough with respect to the amplitude of the noise to yield overwhelmingly non-negative coefficients; technically, this represents a 'measurable' function. We first generalize known results about sub-exponential transmission from regular (almost everywhere continuous) to merely measurable functions with positively- correlated fluctuations. Another interesting outcome is that, in this very general measure-based framework, one can use conventional (continuum-limit) transport theory to address negatively- as well as positively-correlated stochastic media. We thus resolve a controversy concerning recent claims that only discrete-point process approaches can accommodate negative correlations, i.e., anti-clustering of the obstructing material particles. We obtain in this case the predicted super-exponential behavior, but only over a limited range of transport distances. (authors)

  4. Thallium Transfer from Hydrochloric Acid Media into Pure Ionic Liquids.

    Tereshatov, Evgeny E; Boltoeva, Maria Yu; Mazan, Valerie; Volia, Merinda F; Folden, Charles M

    2016-03-10

    Pure hydrophobic ionic liquids are known to extract metallic species from aqueous solutions. In this work we have systematically investigated thallium (Tl) extraction from aqueous hydrochloric acid (HCl) solutions into six pure fluorinated ionic liquids, namely imidazolium- and pyrrolidinium-based ionic liquids with bis(trifluoromethanesulfonyl)imide and bis(fluorosulfonyl)-imide anions. The dependence of the Tl extraction efficiency on the structure and composition of the ionic liquid ions, metal oxidation state, and initial metal and aqueous acid concentrations have been studied. Tl concentrations were on the order of picomolar (analyzed using radioactive tracers) and millimolar (analyzed using inductively coupled plasma mass spectrometry). The extraction of the cationic thallium species Tl(+) is higher for ionic liquids with more hydrophilic cations, while for the TlX(z)(3-z) anionic species (where X = Cl(-) and/or Br(-)), the extraction efficiency is greater for ionic liquids with more hydrophobic cations. The highest distribution value of Tl(III) was approximately 2000. An improved mathematical model based on ion exchange and ion pair formation mechanisms has been developed to describe the coextraction of two different anionic species, and the relative contributions of each mechanism have been determined. PMID:26769597

  5. Electrocatalysis of the HER in acid and alkaline media

    Danilovic Nemanja

    2013-01-01

    Full Text Available Trends in the HER are studied on selected metals (M= Cu, Ag, Au, Pt, Ru, Ir, Ti in acid and alkaline environments. We found that with the exception of Pt, Ir and Au, due to high coverage by spectator species on non-noble metal catalysts, experimentally established positions of Cu , Ag, Ru and Ti in the observed volcano relations are still uncertain. We also found that while in acidic solutions the M-Hupd binding energy most likely is controlling the activity trends, the trends in activity in alkaline solutions are controlled by a delicate balance between two descriptors: the M-Had interaction as well as the energetics required to dissociate water molecules. The importance of the second descriptor is confirmed by introducing bifunctional catalysts such as M modified by Ni(OH; e.g. while the latter serves to enhance catalytic decomposition of water, the metal sites are required for collecting and recombining the produced hydrogen intermediates.

  6. Failure of multi-layer graphene coatings in acidic media

    Yu, Feng; Stoot, Adam Carsten; Bøggild, Peter;

    2016-01-01

    Being impermeable to all gases, graphene has been proposed as an effective ultrathin barrier film and protective coating. However, here it is shown how the gastight property of graphene-based coatings may indirectly lead to their catastrophic failure under certain conditions. When nickel coated...... with thick, high-quality chemical vapor deposited multilayered graphene is exposed to acidic solutions, a dramatic evolution of gas is observed at the coating–substrate interface. The gas bubbles grow and merge, eventually rupturing and delaminating the coating. This behavior, attributed to cathodic...... hydrogen evolution, can also occur spontaneously on a range of other technologically important metals and alloys based on iron, zinc, aluminum and manganese; this makes these findings relevant for practical applications of graphene-based coatings.Being impermeable to all gases, graphene has been proposed...

  7. Determination and Correlation of Solubility for D-Xylose in Volatile Fatty Acid Solvents

    李涛; 陈飞雄; 江振西; 任保增

    2014-01-01

    The solubility of D-xylose in formic acid and binary solvents of formic acid with formic acid and acetic acid, propionic acid, n-butyric acid or isobutyric acid was measured in the temperature range from 300.35 to 325.05 K using the synthetic method by a laser monitoring technique at atmospheric pressure. The solid-liquid equilibrium data will provide essential support for industrial design and further theoretical study. The experimental data show that the solubility of D-xylose in formic acid and in the mixtures of formic acid+acetic acid (1︰1), formic acid+propionic acid (1︰1), formic acid+n-butyric acid (1︰1), and formic acid+isobutyric acid (1︰1) increases with temperature. The Apelblat equation, theλh model, and the ideal solution equation correlate the solubility data well.

  8. CHRONIC OTITIS MEDIA: HIGH RESOLUTION COMPUTED TOMOGRAPHIC EVALUATION OF THE TEMPORAL BONE WITH SURGICAL CORRELATION

    Chakenahalli P.

    2016-05-01

    Full Text Available PURPOSE To correlate the sensitivity and specificity of High Resolution Computed Tomography (HRCT findings of temporal bone in chronic otitis media with surgical findings. MATERIALS & METHODS HRCT of temporal bone of fifty patients with chronic otitis media were evaluated prospectively between July 2012 and December 2013. The various pathological findings, complications and important anatomical variations were evaluated. These findings were compared with intraoperative findings. Statistical methods were carried out using SPSS for Windows (Version 16.0 and Minitab (Version 11.0 for windows. The sensitivity, specificity, false positive and false negative rates were calculated. The level of significance was considered significant for P-values <0.05. RESULTS HRCT is reliable for all the parameters like scutum erosion, ossicular erosion, mastoid pneumatisation, low lying dura, anterior lying sigmoid, Korner’s septum, cholesteatoma extension in middle ear and mastoid, and presence of complications like mastoiditis, mastoid abscess, mastoid cortex dehiscence, sigmoid sinus plate erosion, facial canal dehiscence, tegmen mastoideum erosion, labyrinthine fistula and intracranial complications with a P value <0.05 but not reliable for tegmen tympani erosion and posterior fossa dural plate erosion. Among the findings related to adjacent neurovascular structures, facial canal dehiscence was commonest followed by anterior lying sigmoid sinus and low lying dura. In ossicular erosion, incus was most commonly involved followed by stapes and malleus. Most of the mastoid in this study was sclerotic followed by pneumatised and diploic. The epitympanum and mastoid antrum were the most commonly involved areas in cholesteatoma followed by aditus, mastoid air cells, posterior tympanum, mesotympanum, hypotympanum, protympanum and perilabyrinthine air cells in decreasing order of frequency. CONCLUSIONS HRCT temporal bone is a reliable investigation in preoperative

  9. Correlation between gastric acid secretion and severity of acid reflux in children.

    Kalach, Nicolas; Badran, Abdul Monem; Jaffray, Patrick; Campeotto, Florence; Benhamou, Pierre Henri; Dupont, Christophe

    2003-01-01

    The purpose of our study was to systematically evaluate gastric acid output in children with long-lasting gastro-esophageal reflux (GER) in order to assess its mechanism and the need for anti-acid treatment. The investigation was carried out in 20 males and 10 females, aged 7.5 +/- 3.8 years, with prolonged (>15 months) clinical manifestations of GER. All underwent routine ambulatory 24-h esophageal pH-monitoring and measurement of gastric acid secretion including gastric basal (BAO) (micromol/kg/h), maximal (MAO) and peak acid outputs (PAO) after pentagastrin (6 microg/kg sec) stimulation. Children with heartburn or abdominal pain underwent upper fiber-endoscopy. In group A (moderate GER, n=12), patients had a normal reflux index (pH5.2%. When considering all children, esophageal pH (%) was significantly correlated with MAO and PAO, r=0.33, p=0.05 and r=0.37, p=0.04, respectively. Children of group B exhibited significantly higher BAO (75, 53.96-137.81), MAO (468, 394.1-671.3) and PAO (617, 518.8-782.3) than those of group A, BAO (27, 10.8-38.5), MAO (266, 243.2-348.2) and PAO (387, 322.5-452.7), p<0.05). The five children of group B with severe esophagitis exhibited significantly higher BAO, MAO and PAO than the other 13 children from the same group and those of group A, p<0.05. Children with long-lasting and severe GER hyper-secrete gastric acid. Individual variations in gastric acid secretion probably account for variations in gastric acid inhibitor requirements. Anti-secretory treatment is justified in children with long-lasting GER and high pH-metric reflux index. PMID:12718363

  10. Exclusive many-particle diffusion in disordered media and correlation functions for random vertex models

    We consider systems of particles hopping stochastically on d-dimensional lattices with space-dependent probabilities. We map the master equation in a Fock space where the dynamics are given by a quantum Hamiltonian (continuous time) or a transfer matrix resp. (discrete time). We show that under certain conditions the time-dependent two-point density correlation function in N-particle steady state can be computed from the probability distribution of a single particle moving in the same environment. Focussing on exclusion models where the lattice site can be occupied by at most one particle we discuss as an example for such a stochastic process a generalized Heisenberg antiferromagnet where the strength of the spin-spin coupling in space-dependent. In discrete time one obtains for one dimensional systems the diagonal-to-diagonal transfer matrix of the two dimensional six vertex model with space dependent vertex weights. For a random distribution of the vertex weights one obtains a version of the random barrier model describing diffusion of particles in disordered media. We derive exact expressions for the average two-point density correlation function in the presence of weak, correlated disorder. (authors)

  11. Gint2D-T2 correlation NMR of porous media

    Zhang, Yan; Blümich, Bernhard

    2015-03-01

    The internal magnetic field gradient induced in porous media by magnetic susceptibility differences at material interfaces impacts diffusion measurements in particular at high magnetic field and can be used to probe the pore structure. Insight about the relationship between pore space and internal gradient Gint can be obtained from 2D Laplace NMR experiments. When measuring distributions of transverse relaxation times T2 in fluid filled porous media, relaxation and diffusion in internal gradients arise simultaneously and data are often interpreted with the assumption that one or the other parameter be constant throughout the sample. To examine this assumption we measure correlations of the distributions of Gint2D and T2 by 2D Laplace NMR for three different kinds of samples, glass beads with different bead diameters saturated with water, glass beads filled with oil and water, and a wet mortar sample. For the first two samples the cases where either the internal gradient or diffusion dominates were examined separately in order to better understand the relationship between Gint and D. These results are useful for assessing the impact of internal gradients and diffusion in unknown samples, such as the mortar sample. The experiments were performed at different magnetic field strengths corresponding to 300 MHz and 700 MHz 1H Larmor frequency to identify the impact of the magnetic field on the internal gradient. Subsequently, spatially resolved Gint2D-T2 maps were obtained to study the sample heterogeneity.

  12. A Generalized Linear Transport Model for Spatially-Correlated Stochastic Media

    Davis, Anthony B

    2014-01-01

    We formulate a new model for transport in stochastic media with long-range spatial correlations where exponential attenuation (controlling the propagation part of the transport) becomes power law. Direct transmission over optical distance $\\tau(s)$, for fixed physical distance $s$, thus becomes $(1+\\tau(s)/a)^{-a}$, with standard exponential decay recovered when $a\\to\\infty$. Atmospheric turbulence phenomenology for fluctuating optical properties rationalizes this switch. Foundational equations for this generalized transport model are stated in integral form for $d=1,2,3$ spatial dimensions. A deterministic numerical solution is developed in $d=1$ using Markov Chain formalism, verified with Monte Carlo, and used to investigate internal radiation fields. Standard two-stream theory, where diffusion is exact, is recovered when $a=\\infty$. Differential diffusion equations are not presently known when $a<\\infty$, nor is the integro-differential form of the generalized transport equation. Monte Carlo simulations...

  13. In vivo in vitro correlations for a poorly soluble drug, danazol, using the flow-through dissolution method with biorelevant dissolution media

    Sunesen, Vibeke Hougaard; Pedersen, Betty Lomstein; Kristensen, Henning Gjelstrup; Müllertz, Anette

    2005-01-01

    .H., Vedelsdal, R., Kristensen, H.G., Christrup, L., Müllertz, A. 2005. Effect of liquid volume and food intake on the absolute bioavailability of danazol, a poorly soluble drug, Eur. J. Pharm. Sci. 24, 297-303]. In the fasted state, the physiologically most relevant correlation with in vivo results was achieved...... phospholipids, were used as the bile source. The effect of adding different concentrations and molar ratios of monoglycerides and fatty acids to the fed state media was investigated. In vivo release profiles under fasted and fed conditions were obtained from a previous study by deconvolution [Sunesen, V......The purpose of the study was to design dissolution tests that were able to distinguish between the behaviour of danazol under fasted and fed conditions, by using biorelevant media. In vitro dissolution of 100mg danazol capsules was performed using the flow-through dissolution method. Flow rates...

  14. Carotid intima-media thickness correlation with lipid profile in patients with familial hypercholesterolemia versus controls

    To determine the variations in carotid intima-media thickness (CIMT) in familial hypercholesterolemia (FH) patients and its use as predictive marker for premature cardiovascular diseases. Familial hypercholesterolemia was clinically diagnosed by premature coronary diseases, xanthomas, arcus cornealis and family history of premature coronary heart diseases. Controls were age matched normal individuals without hypercholesterolemia. Their lipid profile was tested after overnight fasting. CIMT was measured in mm using B-mode ultrasonography using linear probe. Student t-test was applied to compare mean CIMT of cases and the control. The mean CIMT values of the FH cases were correlated with LDL using Pearson's correlation test. Forty cases with hypercholesterolemia gave consent to participate in the study. These patients had total cholesterol 200 mg/dL and LDL 160 mg/dL as compared to twenty controls of similar age with total cholesterol ? 200 mg/dL and LDL 130 mg/dL. Mean CIMT for the cases was 0.77 + 0.18 mm while mean CIMT for control was 0.59 + 0.08 mm. The mean CIMT for the cases ranged from 0.7-1.83 mm and 0.48-0.73 mm for controls. Among the FH cases, 25% (n=11) had arterial plaques. Mean CIMT was significantly correlated to LDL-cholesterol (r 0.725**, p < 0.001). In this study, CIMT was found to be significantly increased in familial hypercholesterolemia and it correlated with raised LDL-cholesterol. Both are predictive of premature cardiovascular diseases. (author)

  15. In Situ Degradation of Chitosan-Polygalacturonic Acid/Hydroxyapatite Nano composites in Cell Culture Media

    The molecular and mechanical characteristics of in situ degradation behavior of chitosan-polygalacturonic acid/hydroxyapatite (Chi-PgA-HAP) nano composite films is investigated using Fourier Transform Infrared spectroscopy (FTIR), Atomic Force Microscopy (AFM), and modulus mapping techniques for up to 48 days of soaking in cell culture media. The surface molecular structure of media-soaked samples changes over the course of 48 days of soaking, as indicated by significant changes in phosphate vibrations (1200-900cm-1) indicating apatite formation. Chitosan-Polygalacturonic acid polyelectrolyte complexes (PECs) govern structural integrity of Chi-PgA-HAP nano composites and FTIR spectra indicate that PECs remain intact until 48 days of soaking. In situ AFM experiments on media-soaked samples indicate that soaking results in a change in topography and swelling proceeds differently at the initial soaking periods of about 8 days than for longer soaking. In situ modulus mapping experiments are done on soaked samples by probing 13 nm of surface indicating elastic moduli of 4 GPa resulting from proteins adsorbed on Chi-PgA-HAP nano composites. The elastic modulus decreases by 2 GPa over a long exposure to cell culture media (48 days). Thus, as water enters the Chi-PgA-HAP sample, surface molecular interactions in Chi-PgA-HAP structure occur that result in swelling, causing small changes in nano scale mechanical properties.

  16. Ionic flotation of uranium and of cadmium in concentrated phosphoric acid media

    The ionic flotation technique has been applied to concentrated phosphoric acid media (with 30% P2O5 or H3PO4 5.5 M) as a new process for the recovery of uranium and the elimination of cadmium. The results obtained seem to indicate that in these hyperacid media the anionic collectors are better suited than the cationic collectors and that they then permit the flotation of the uranium and cadmium ions with a very rapid kinetics and the achievement of efficiencies of over 90%. In the case of uranium, the collector used remains efficient up to a temperature of 600C with a satisfactory selectivity in the face of others cations present in the commercial phosphoric acid, and which have a penalizing effect on the uraniferous concentrates, and the floated uranium concentrate assays approximately 10% U on a dry basis

  17. Aqueous citric acid as green reaction media for the synthesis of octahydroxanthenes

    Camilo A. Navarro D.; Cesar A. Sierra; Cristian Ochoa-Puentes

    2013-01-01

    A simple, convenient and environmentally friendly one-pot procedure for the synthesis of 1,8-dioxo-octahydroxanthenes by the reaction of dimedone and aromatic aldehydes in aqueous citric acid is described. In this green synthetic protocol promoted by the reaction media, the use of any other catalysts and hazardous organic solvents are avoided, making the work up procedure greener and easier. The isolation of the products, obtained in good yields, is readily performed by filtration and crystal...

  18. Electrochemical features of Pt(S)[n(110) × (100)] surfaces in acidic media

    Souza-Garcia, Janaina; Angelucci, Camilo Andrea; Climent, Víctor; Feliu, Juan M.

    2013-01-01

    Experiments have been carried out in sulfuric and perchloric acid solutions on Pt(S)[n(110) × (100)] electrodes. The comparison between the two different electrolytic media reveals an important influence of the anion in the voltammetric features. Total charge curves have been obtained with the CO charge displacement method in combination with voltammetric measurements. From these curves, the dependence of the pztc with the step density and the strength of the anion adsorption have been analyz...

  19. Study of Plant Cordia Dichotoma as Green Corrosion Inhibitor for Mild Steel in Different Acid Media

    Khandelwal, R; Arora, S. K.; Mathur, S P

    2011-01-01

    The corrosion inhibition of mild steel using extracts of Cordia dichotoma in different acid media was investigated by mass loss and thermometric methods. The experiments were carried out at 299±0.2 K in presence of different concentrations of dry fruit, leaves and stem extracts of Cordia dichotoma. The results reveal that the alcoholic extracts of Cordia dichotoma is a better corrosion inhibitor than that of toxic chemicals. The fruit extract is more potent than leaves and stem extracts to in...

  20. Molecular dynamics study of solvation effects on acid dissociation in aprotic media

    Laria, Daniel; Kapral, Raymond; Estrin, Dario; Ciccotti, Giovanni

    1996-01-01

    Acid ionization in aprotic media is studied using Molecular Dynamics techniques. In particular, models for HCl ionization in acetonitrile and dimethylsulfoxide are investigated. The proton is treated quantum mechanically using Feynman path integral methods and the remaining molecules are treated classically. Quantum effects are shown to be essential for the proper treatment of the ionization. The potential of mean force is computed as a function of the ion pair separation and the local solven...

  1. Optimization of culture media for enhancing gamma-linolenic acid production by Mucor hiemalis

    Mina Mohammadi Nasr

    2016-03-01

    Full Text Available Introduction: g-linolenic acid is an essential fatty acid in human nutrition. In the present study, production of g-linolenic acid by Mucor hiemalis PTCC 5292 was evaluated in submerged fermentation. Materials and methods: The fermentation variables were chosen according to the fractional factorial design and further optimized via full factorial method. Four significant variables, glucose, peptone, ammonium nitrate and pH were selected for the optimization studies. The design consisted of total 16 runs consisting of runs at two levels for each factor with three replications of the center points. Results: The analysis of variance and three-dimensional response surface plot of effects indicated that variables were regarded to be significant for production of g-linolenic acid by Mucor hiemalis. Results indicated that fermentation at the optimum conditions (100 g/l glucose concentration; 1 g/l peptone; 1 g/l ammonium nitrate, and pH of 4.5 enhanced the g-linolenic acid production up to 709 mg/l. Discussion and conclusion: The results of this study indicated that higher g-linolenic acid yield can be achieved in a simple medium at high glucose and ammonium nitrate, low peptone concentrations and acidic pH by Mucor hiemalis PTCC 5292. This simple and low cost optimization condition of culture media can be applied for g-linolenic acid production at higher scale for pharmaceutical and nutritional industries. 

  2. Evaluating Potential Bias in Media Coverage of the Public Debate over Acid Rain and Chlorofluorocarbons in the 1980s

    Williams, Tiffany Dawn; Moore, Rebecca; Markewitz, Daniel

    2012-01-01

    This study evaluates media coverage of two important environmental issues from the 1980s (acid rain and chlorofluorocarbons), providing historical context for current media coverage analysis. Focusing on popular magazine articles, this study identifies key characteristics of content and presentation. Content-related characteristics are inclusion…

  3. Poly(acrylic acid) coating induced 2-line ferrihydrite nanoparticle transport in saturated porous media

    Iron oxide and iron nanoparticles (NPs) have been used effectively for environmental remediation, but are limited in their applications by strong retention in groundwater-saturated porous media. For example, delivery of NPs to large groundwater reservoirs would require large numbers of injection wells. To address this problem, we have explored polymer coatings as a surface engineering strategy to enhance transport of oxide nanoparticles in porous media. We report here on our studies of 2-line ferrihydrite NPs and the influence of poly (acrylic acid) (PAA) polymer coatings on the colloidal stability and transport in natural sand-packed column tests simulating flow in groundwater-saturated porous media. Measurements were also made of zeta potential, hydrodynamic diameter, and polymer adsorption and desorption properties. The coated NPs have a diameter range of 30–500 nm. We found that NP transport was improved by PAA coating and that the transport properties could be tuned by adjusting the polymer concentration. Our results demonstrate that a high stability of oxide particles and improved transport can be achieved in groundwater-saturated porous media by introducing negatively charged polyelectrolytes and optimizing polymer concentrations

  4. Poly(acrylic acid) coating induced 2-line ferrihydrite nanoparticle transport in saturated porous media

    Xiang, Aishuang [Princeton University, Chemical and Biological Engineering Department (United States); Yan, Weile [Texas Tech University, Civil and Environmental Engineering (United States); Koel, Bruce E., E-mail: bkoel@princeton.edu [Princeton University, Chemical and Biological Engineering Department (United States); Jaffe, Peter R., E-mail: jaffe@princeton.edu [Princeton University, Civil and Environmental Engineering Department (United States)

    2013-07-15

    Iron oxide and iron nanoparticles (NPs) have been used effectively for environmental remediation, but are limited in their applications by strong retention in groundwater-saturated porous media. For example, delivery of NPs to large groundwater reservoirs would require large numbers of injection wells. To address this problem, we have explored polymer coatings as a surface engineering strategy to enhance transport of oxide nanoparticles in porous media. We report here on our studies of 2-line ferrihydrite NPs and the influence of poly (acrylic acid) (PAA) polymer coatings on the colloidal stability and transport in natural sand-packed column tests simulating flow in groundwater-saturated porous media. Measurements were also made of zeta potential, hydrodynamic diameter, and polymer adsorption and desorption properties. The coated NPs have a diameter range of 30-500 nm. We found that NP transport was improved by PAA coating and that the transport properties could be tuned by adjusting the polymer concentration. Our results demonstrate that a high stability of oxide particles and improved transport can be achieved in groundwater-saturated porous media by introducing negatively charged polyelectrolytes and optimizing polymer concentrations.

  5. Immiscible fluids in mixed wet porous media: the role of wettability correlations

    Murison, Julie; Semin, Benoit; Baret, Jean-Christophe; Herminghaus, Stephan; Schroeter, Matthias; Brinkmann, Martin

    2013-11-01

    Various phenomena observed during immiscible displacement in a porous medium can be related to pore wall wettability. Petroleum engineers traditionally quantify the overall wettability of a rock sample in terms of the Ammot-Harvey or USBM index. To establish a link between these gloabl quantities and the pore-scale distribution of surface energies, we developed a series of model porous media. Using a variety of preparation methods, we are able to create dense beds of glass beads with the same average surface energy, differing only in the typical extension of the wetting and non-wetting surface domains. Experimental measurements of capillary pressure saturation curves for repeated imbibition and drainage show that the work dissipated in a complete cycle is monotonically increasing with the correlation length ξ of the surface energies. To test whether capillary hysteresis can be linked to specific features of the front morphology, we visualized the distribution of liquids by means of X-ray microtomography. The Minkowski measures volume, surface area, and Euler number are employed to characterize the interfacial shape. Differences of the front morphology during imbibition and drainage match with trends observed for the hysteresis loop opening.

  6. Effects of multiple scattering on fluorescence correlation spectroscopy measurements of particles moving within optically dense media.

    Zustiak, Silviya; Riley, Jason; Boukari, Hacène; Gandjbakhche, Amir; Nossal, Ralph

    2012-12-01

    Fluorescence correlation spectroscopy (FCS) is increasingly being used to assess the movement of particles diffusing in complex, optically dense surroundings, in which case measurement conditions may complicate data interpretation. It is considered how a single-photon FCS measurement can be affected if the sample properties result in scattering of the incident light. FCS autocorrelation functions of Atto 488 dye molecules diffusing in solutions of polystyrene beads are measured, which acted as scatterers. Data indicated that a scattering-linked increase in the illuminated volume, as much as two fold, resulted in minimal increase in diffusivity. To analyze the illuminated beam profile, Monte-Carlo simulations were employed, which indicated a larger broadening of the beam along the axial than the radial directions, and a reduction of the incident intensity at the focal point. The broadening of the volume in the axial direction has only negligible effect on the measured diffusion time, since intensity fluctuations due to diffusion events in the radial direction are dominant in FCS measurements. Collectively, results indicate that multiple scattering does not result in FCS measurement artifacts and thus, when sufficient signal intensity is attainable, single-photon FCS can be a useful technique for measuring probe diffusivity in optically dense media. PMID:23208294

  7. Social Media Use, Loneliness, and Academic Achievement: A Correlational Study with Urban High School Students

    Neto, Roque; Golz, Nancy; Polega, Meaghan

    2015-01-01

    This study explored the association between social media use, loneliness, and academic achievement in high school students and identified the demographic characteristics associated with these three elements. This study also aimed to identify the percentage of variance in loneliness accounted for by social media use and GPA. Participants were 345…

  8. Acidic Properties and Structure-Activity Correlations of Solid Acid Catalysts Revealed by Solid-State NMR Spectroscopy.

    Zheng, Anmin; Li, Shenhui; Liu, Shang-Bin; Deng, Feng

    2016-04-19

    Solid acid materials with tunable structural and acidic properties are promising heterogeneous catalysts for manipulating and/or emulating the activity and selectivity of industrially important catalytic reactions. On the other hand, the performances of acid-catalyzed reactions are mostly dictated by the acidic features, namely, type (Brønsted vs Lewis acidity), amount, strength, and local environment of acid sites. The latter is relevant to their location (intra- vs extracrystalline), and possible confinement and Brønsted-Lewis acid synergy effects that may strongly affect the host-guest interactions, reaction mechanism, and shape selectivity of the catalytic system. This account aims to highlight some important applications of state-of-the-art solid-state NMR (SSNMR) techniques for exploring the structural and acidic properties of solid acid catalysts as well as their catalytic performances and relevant reaction pathway invoked. In addition, density functional theory (DFT) calculations may be exploited in conjunction with experimental SSNMR studies to verify the structure-activity correlations of the catalytic system at a microscopic scale. We describe in this Account the developments and applications of advanced ex situ and/or in situ SSNMR techniques, such as two-dimensional (2D) double-quantum magic-angle spinning (DQ MAS) homonuclear correlation spectroscopy for structural investigation of solid acids as well as study of their acidic properties. Moreover, the energies and electronic structures of the catalysts and detailed catalytic reaction processes, including the identification of reaction species, elucidation of reaction mechanism, and verification of structure-activity correlations, made available by DFT theoretical calculations were also discussed. Relevant discussions will focus primarily on results obtained from our laboratories in the past decade, including (i) quantitative and qualitative acidity characterization utilizing assorted probe molecules

  9. Investigations of corrosion films formed on API-X52 pipeline steel in acid sour media

    Hernandez-Espejel, A. [Instituto Politecnico Nacional, Departamento de Ingenieria Metalurgica, IPN-ESIQIE, UPALM Ed. 7, Zacatenco 07738, Mexico, D.F. (Mexico); Dominguez-Crespo, M.A. [Instituto Politecnico Nacional, CICATA-Unidad Altamira-Tamaulipas, km 14.5, Carretera Tampico-Puerto Industrial Altamira, 89600 Altamira, Tamps (Mexico); Cabrera-Sierra, R. [Instituto Politecnico Nacional, Departamento de Ingenieria Quimica Industrial, IPN-ESIQIE, UPALM Ed. 7, Zacatenco 07738, Mexico, D.F. (Mexico); Rodriguez-Meneses, C. [Instituto Politecnico Nacional, Departamento de Ingenieria Metalurgica, IPN-ESIQIE, UPALM Ed. 7, Zacatenco 07738, Mexico, D.F. (Mexico); Arce-Estrada, E.M., E-mail: earce@ipn.m [Instituto Politecnico Nacional, Departamento de Ingenieria Metalurgica, IPN-ESIQIE, UPALM Ed. 7, Zacatenco 07738, Mexico, D.F. (Mexico)

    2010-07-15

    Corrosion films formed by voltammetry using different switching potentials and by immersion on API-X52 pipeline steel in simulated acid sour media (NACE ID182) have been characterized using Scanning Electron Microscopy (SEM), X-ray Diffraction (XRD), Linear Polarization and Electrochemical Impedance Spectroscopy (EIS) techniques. XRD and EDS analysis showed that the films are mainly composed of sulphide compounds (mackinawite, troilite, marcasite and pyrite) as well as iron oxides, as steel damage increases. Across SEM micrographs the corrosion films formed by potentiodynamic and immersion tests are very similar, covering most of the steel. Polarization and EIS results corroborate poor behavior against corrosion.

  10. Investigations of corrosion films formed on API-X52 pipeline steel in acid sour media

    Corrosion films formed by voltammetry using different switching potentials and by immersion on API-X52 pipeline steel in simulated acid sour media (NACE ID182) have been characterized using Scanning Electron Microscopy (SEM), X-ray Diffraction (XRD), Linear Polarization and Electrochemical Impedance Spectroscopy (EIS) techniques. XRD and EDS analysis showed that the films are mainly composed of sulphide compounds (mackinawite, troilite, marcasite and pyrite) as well as iron oxides, as steel damage increases. Across SEM micrographs the corrosion films formed by potentiodynamic and immersion tests are very similar, covering most of the steel. Polarization and EIS results corroborate poor behavior against corrosion.

  11. Effect of acidity on the polarization sensitivity of azo-indicator based recording media*

    Shaverdova, V. G.; Petrova, S. S.; Purtseladze, A. L.; Tarasashvili, V. I.; Obolashvili, N. Z.

    2013-01-01

    This is an experimental study of the photoanisotropic gyrotropic properties of recording media based on azoindicators — homologs (five dyes) of methyl orange-- introduced into the polymer matrix. Samples were prepared by a technology we have developed employing solvents with different acidities (pH 1.68-12.48). The samples were exposed to actinic radiation (λ = 488 nm) from an argon laser, and the photoinduced anisotropy measured in real time. The circular dichroism and circular birefringence in the layers under study are calculated for a neutral medium and at different pH levels.

  12. Interaction in the boron-fluorine-molybdenum system in hydrochloric acid media

    Existence of heteropolycompounds of the 12-th order with the Keggin structure in the boron-fluorine-molybdenum system in hydrochloric acid media (pH 2.0-2.5) is determined through the spectroscopy (UV, visible, IR, Raman) methods. Its ability to reversible reduction without destruction of the basic structure through monoelectron transition Mo(6) -> Mo(5) is shown. The reduced form is characterized by the component ratio B:F:Mo(5) = 1:3:1 and may be described by brutto formula [BMo5Mo611O38F3]5-. 18 refs., 8 figs

  13. Determination of uranium isotopes in environmental samples by anion exchange in sulfuric and hydrochloric acid media.

    Popov, L

    2016-09-01

    Method for determination of uranium isotopes in various environmental samples is presented. The major advantages of the method are the low cost of the analysis, high radiochemical yields and good decontamination factors from the matrix elements, natural and man-made radionuclides. The separation and purification of uranium is attained by adsorption with strong base anion exchange resin in sulfuric and hydrochloric acid media. Uranium is electrodeposited on a stainless steel disk and measured by alpha spectrometry. The analytical method has been applied for the determination of concentrations of uranium isotopes in mineral, spring and tap waters from Bulgaria. The analytical quality was checked by analyzing reference materials. PMID:27451111

  14. Cu-Co-Ni alloys: an efficient and durable electrocatalyst in acidic media

    Saha, Soumen; Ramanujachary, Kandalam V.; Lofland, Samuel E.; Ganguli, Ashok K.

    2016-01-01

    We have developed efficient nanostructures of Cu-Co-Ni alloy with varied stoichiometry as an alternative to the costly Pt-based alloys for hydrogen evolution reaction (HER). These nanoparticles were synthesized using the reverse micellar method. The size of the alloy nanoparticles varied from 40 to 70 nm. An enhanced catalytic activity as evident from high current density was observed for these Cu-Co-Ni (111) alloys which follows the Volmer-Heyrovsky mechanism. They have excellent stability (up to 500 cycles) and significant activity in acid media which might be due to the low hydrogen binding energy.

  15. Possible applications of granular media (filtration, coalescence) in circuits of uranium recovery from phosphoric acid

    The uranium recovery from phosphoric acid poses two more specific problems: the necessity of a good clarification of the phosphoric acid before the extraction by an organic solvent; the necessity of an efficient recovery of the residual solvent in the phosphoric acid, freed from uranium, and if necessary, in the wash water. To solve these problems, the application of granular media can furnish a simple and economical solution, by: filtrating through sand and/or anthracite on the first case; coalescence through sand in the second case. The tests which were carried out on pilot circuits have given the following results: 1) Filtration tests on green acid: the best results were obtained with a maximum filtration speed of 7,5 m/h over a height of 1 m min of anthracite from 1.2 to 2.4 mm, with a lagging which permits the prevention of a temperature drop leading to the precipitation of gypsum; 2) Coalescence applied to green acid, free from uranium: to achieve a residual content of less than 5 mg/l, it is necessary to apply a double coalescence, the first functioning without any chemical reagent, and the second with an injection of a specific cationic polymer; 3) Coalescence applied to the wash solution: washing of the solvent effected in water before the re-extration of the uranium; the treated solution contains from 10 to 20 mg/l of residual solvent on an average and can be re-used practically without any complementary treatment

  16. Carbonate minerals in porous media decrease mobility of polyacrylic acid modified zero-valent iron nanoparticles used for groundwater remediation

    The limited transport of nanoscale zero-valent iron (nZVI) in porous media is a major obstacle to its widespread application for in situ groundwater remediation. Previous studies on nZVI transport have mainly been carried out in quartz porous media. The effect of carbonate minerals, which often predominate in aquifers, has not been evaluated to date. This study assessed the influence of the carbonate minerals in porous media on the transport of polyacrylic acid modified nZVI (PAA-nZVI). Increasing the proportion of carbonate sand in the porous media resulted in less transport of PAA-nZVI. Predicted travel distances were reduced to a few centimeters in pure carbonate sand compared to approximately 1.6 m in quartz sand. Transport modeling showed that the attachment efficiency and deposition rate coefficient increased linearly with increasing proportion of carbonate sand. -- Highlights: •Mobility of nZVI NANOFER 25S was investigated in different saturated porous media. •nZVI transport in carbonate-containing porous media was elucidated and quantified. •Mobility of polyacrylic acid-coated nZVI significantly ceases in carbonate-containing media. •Deposition rate coefficient increases linearly with increasing carbonate content. -- Carbonate minerals in porous aquifers significantly decrease the mobility of commercially available polyacrylic acid modified nanoscale zero-valent iron

  17. Social Media Usage In European Clubs Football Industry. Is Digital Reach Better Correlated With Sports Or Financial Performane?

    Teodor Dima

    2015-03-01

    Full Text Available Social media is likely the marketing and communication channel which grew fastest from "unique and modern" to "mandatory". Presented as a solution for the future, usage of media channels has already become a key part of any brand promoting campaign or business expansion effort. And football clubs line up with this trend. Development of the new media elements solves two fundamental needs for business units specialized in sports: the need for faster and more efficient communication with fans - a true two-way relationship - and the need to expand the base of supporters using marketing tools. This paper presents the usage of social media networks in European club football industry, the mix of channels used and the increase of digital supporters for the top teams. This academic approach also examines the correlation between the digital reach of the richest clubs in the world and their sports and financial results. This study shows the growing importance that social media plays in the sports industry, initiating a debate on the relationship between the digital expansion of a football club and its sports and financials indicators.

  18. Correlation between malondialdehyde (MDA and uric acid levels in preeclampsia

    T. Sharmila Krishna

    2015-06-01

    Conclusion: Serum MDA and uric acid may be included as additional markers for screening and progression of preeclampsia, thereby helpful in effectively treating the condition at an early stage. [Int J Res Med Sci 2015; 3(6.000: 1443-1445

  19. Monitoring Lactic Acid Fermentation in Media Containing Dandelion (Taraxacum officinale by FTIR Spectroscopy

    Dan C. VODNAR

    2012-05-01

    Full Text Available Fourier-transform infrared (FTIR spectroscopy is considered to be a comprehensive and sensitive method for detection of molecular changes in cells and media. In the present study, FTIR spectroscopy was employed as an easy, rapid and reliable technique to evaluate the lactic fermentation of Lactobacillus casei on a model de Man, Rogosa and Sharpe (MRS medium with or without the addition of dandelion extract (DE. Dandelion, due to its high content in fructans, can be used as an additional carbon source in lactic fermentation. Lactic fermentation in a dandelion extract, using the FTIR fingerprint as a qualitative and semi-quantitative assay for lactic acid production was monitored. Specific bands of carbohydrates in the fingerprint region (1200-900 cm-1 and their shifts indicated the hydrolysis and metabolism during fermentation. The band at 1336 cm-1 may be considered a sensitive marker for the identification of L. casei during fermentation, while the dandelion extract showed a unique characteristic peak at 1436 cm-1. The results proved that the species were detectable and that significant spectral differences existed between fermented samples in media with or without dandelion addition. Representative peaks of bacteria and dandelion appeared in the spectra of a mixture of bacteria and dandelion. The peaks were evident in the samples taken using the model MRS media from the beginning of fermentation as opposed to at the end of fermentation.

  20. Ozonation of azo dyes (Orange II and Acid Red 27) in saline media

    Ozonation of two azo dyes was investigated in a monitored bench scale bubble column reactor (8.5-L), varying liquid media salt content (0, 1, 40 and 100 g L-1, NaCl). In experiments with Orange II pH was varied (5, 7.5 and 9) but ozonation of Acid Red 27 was performed at pH 7.5. Ozone self-decomposition rate-constant increased with salt concentration. Color removal was very effective and fast achieved under all experimental conditions. For the two azo dyes tested, more than 98% of color intensity was removed in 30-min ozonation assays. However, only partial mineralization of azo dyes (45%-Orange II; 20%-Acid Red 27) was attained in such experiments. The degree of mineralization (TOC removal) was negatively affected by salt concentration. Biodegradation assays conducted by respirometry revealed the inhibitory effect of dye degradation products formed during ozonation.

  1. Correlates of mobile screen media use among children aged 0–8: protocol for a systematic review

    Paudel, Susan; Leavy, Justine; Jancey, Jonine

    2016-01-01

    Background Childhood is a crucial period for shaping healthy behaviours; however, it currently appears to be dominated by screen time. A large proportion of young children do not adhere to the screen time recommendations, with the use of mobile screen devices becoming more common than fixed screens. Existing systematic reviews on correlates of screen time have focused largely on the traditional fixed screen devices such as television. Reviews specially focused on mobile screen media are almos...

  2. Impact of climate changes and correlations on oil fatty acids in sunflower

    Sunflower oil is a major important vegetable oil because it is widely used in human nutrition and in many industrial productions depends on fatty acid composition. Field studies were conducted during in two years on the same soil to investigate changes of climate induced oil fatty acid composition of a traditional sunflower, and to obtain correlations among oil fatty acids. Seed oil content and twelve fatty acid percentages of sunflower oil were analyzed. Variations for years were significant for seed oil content and palmitic acid (C16:0), oleic (C18:1), linoleic (C18:2), linolenic (C18:3), miristic (C14:0) and eicosenoic acids (C20:1). Higher temperatures during seed development in 2010 resulted with 68.38 % increasing in oleic content of the traditional sunflower hybrid. The highest negative correlations (r= -0.99) were noted between oleic and linoleic acids. (author)

  3. Corrosion Study of Stainless Steels in Peracetic Acid Bleach Media With and Without Chloride and Chelant

    Rohtash

    2014-12-01

    Full Text Available The paper industries are adopting non-chlorine containing chemicals e.g. peroxide, ozone, peracids etc. as alternate of chlorine based bleach chemicals e.g. chlorine and chlorine dioxide etc. with the aim of eco-friend atmospheres. Changeover to the new chemicals in the bleaching process is likely to affect the metallurgy of the existing bleach plants due to change in the corrosivity of the media. Accordingly, corrosion investigations were performed in a peracid namely peracetic acid to test the suitability of austenitic stainless steels 654SMO, 265SMO, 2205, 317L and 316L. The performance of above stainless steels was evaluated through long term immersion tests and Electrochemical polarization measurements in peracetic acid (PAA bleach media at pH value 4 maintaining concentration 0.2 % as active oxygen along with three chloride levels 0, 500 and 1000 ppm in pulp-free laboratory. To study the effect of corrosion inhibitors with extending limit of chloride in liquors, measurements were also made with two types of chelants- EDTA & MgSO4. The results showed that corrosivity of PAA reduced by addition of chelant while increased with concentration of Cl¯. The results also exhibited that EDTA is better inhibitor than MgSO4.

  4. Correlation between fibroin amino acid sequence and physical silk properties.

    Fedic, Robert; Zurovec, Michal; Sehnal, Frantisek

    2003-09-12

    The fiber properties of lepidopteran silk depend on the amino acid repeats that interact during H-fibroin polymerization. The aim of our research was to relate repeat composition to insect biology and fiber strength. Representative regions of the H-fibroin genes were sequenced and analyzed in three pyralid species: wax moth (Galleria mellonella), European flour moth (Ephestia kuehniella), and Indian meal moth (Plodia interpunctella). The amino acid repeats are species-specific, evidently a diversification of an ancestral region of 43 residues, and include three types of regularly dispersed motifs: modifications of GSSAASAA sequence, stretches of tripeptides GXZ where X and Z represent bulky residues, and sequences similar to PVIVIEE. No concatenations of GX dipeptide or alanine, which are typical for Bombyx silkworms and Antheraea silk moths, respectively, were found. Despite different repeat structure, the silks of G. mellonella and E. kuehniella exhibit similar tensile strength as the Bombyx and Antheraea silks. We suggest that in these latter two species, variations in the repeat length obstruct repeat alignment, but sufficiently long stretches of iterated residues get superposed to interact. In the pyralid H-fibroins, interactions of the widely separated and diverse motifs depend on the precision of repeat matching; silk is strong in G. mellonella and E. kuehniella, with 2-3 types of long homogeneous repeats, and nearly 10 times weaker in P. interpunctella, with seven types of shorter erratic repeats. The high proportion of large amino acids in the H-fibroin of pyralids has probably evolved in connection with the spinning habit of caterpillars that live in protective silk tubes and spin continuously, enlarging the tubes on one end and partly devouring the other one. The silk serves as a depot of energetically rich and essential amino acids that may be scarce in the diet. PMID:12816957

  5. Correlation between malondialdehyde (MDA) and uric acid levels in preeclampsia

    T. Sharmila Krishna; E.Venkata Rao; Sowjanya, B.; A. Saseekala; Naidu, J.N.

    2015-01-01

    Background: Hypertensive disorders of human pregnancy, such as preeclampsia, complicates a sizeable percentage of all pregnancies, need its early indication and warning. The aim of present study was to determine the association between lipid peroxidation product, serum malondialdehyde (MDA) and serum uric acid levels in preeclampsia and find out any association between these two parameters in preeclampsia. Methods: Thirty preeclampsia and thirty gestational age matched normotensive pregna...

  6. Correlated Mutations: A Hallmark of Phenotypic Amino Acid Substitutions

    Kowarsch, Andreas; Fuchs, Angelika; Frishman, Dmitrij; Pagel, Philipp

    2010-01-01

    Point mutations resulting in the substitution of a single amino acid can cause severe functional consequences, but can also be completely harmless. Understanding what determines the phenotypical impact is important both for planning targeted mutation experiments in the laboratory and for analyzing naturally occurring mutations found in patients. Common wisdom suggests using the extent of evolutionary conservation of a residue or a sequence motif as an indicator of its functional importance an...

  7. The Revolution Will Be Televised: Identifying, Organizing, and Presenting Correlations Between Social Media and Broadcast Television

    Riley, Patrick F

    2011-01-01

    Many popular facets of live information, known collectively as communication technology, deliver ongoing, socially-relevant narrations of our world. Traditionally, different types of communication media were considered to be in competition, but recently they have been discovered to be complementary and synergistic. This paper will concentrate on the role, influence, and potential of the integration of various types of communication media with particular attention to the recent phenomenon of s...

  8. Mobility of acid-treated carbon nanotubes in water-saturated porous media.

    Peng, X J; Du, C J; Liang, Z; Wang, J; Luan, Z K; Li, W J

    2011-01-01

    The production, use, and disposal of nanomaterials may inevitably lead to their appearance in water. With the development of new industries around nanomaterials, it seems necessary to be concerned about the transport of nanomaterials in the environment. In this paper, the transport of acid-treated carbon nanotubes (CNTs) in porous media was investigated. Before the mobility investigation, the stability of acid-treated CNT dispersions was studied using ultraviolet-visible spectra and it was indicated that, under the chemical conditions employed in this work, there was no apparent aggregation. The mobility investigation showed that transport of acid-treated CNTs increased with treatment time due to increase in particle zeta potential. Carbon nanotubes treated with nitric acid for 2, 6, and 12 h possessed measured zeta potentials of -30.0, -43.0, and -48.5 mV, respectively. Utilizing clean-bed filtration theory, we showed that acid-treated CNTs have the potential to migrate 3.28, 5.67, and 7.69 m in saturated glass beads, respectively. We showed that solution ionic strength and pH have important effects on the mobility of acid-treated CNTs. Increasing the pH from 6.0 to 7.9 resulted in an increase in migration potential from 2.96 to 10.86 m. Increasing the ionic strength from 0.005 to 0.020 M resulted in a decrease in CNT migration potential from 5.67 to 1.42 m. PMID:22031583

  9. Individual variation and intraclass correlation in arachidonic acid and eicosapentaenoic acid in chicken muscle

    Olesen Ingrid; Haug Anna; Christophersen Olav A

    2010-01-01

    Abstract Chicken meat with reduced concentration of arachidonic acid (AA) and reduced ratio between omega-6 and omega-3 fatty acids has potential health benefits because a reduction in AA intake dampens prostanoid signaling, and the proportion between omega-6 and omega-3 fatty acids is too high in our diet. Analyses for fatty acid determination are expensive, and finding the optimal number of analyses to give reliable results is a challenge. The objective of the present study was i) to analys...

  10. Dissolution difference between acidic and neutral media of acetaminophen tablets containing a super disintegrant and a soluble excipient. II.

    Chen, C R; Cho, S L; Lin, C K; Lin, Y H; Chiang, S T; Wu, H L

    1998-03-01

    The disintegration and dissolution of acetaminophen tablets containing sucrose and Ac-Di-Sol/Primojel was significantly different between acidic and neutral media. The purpose of this study was to investigate the mechanism of this phenomenon and to propose a way of reducing the dissolution difference between the two media. Tablets of different combinations of active ingredient, sucrose, and Ac-Di-Sol/Primojel were prepared and their dissolution in various media was evaluated. The dissolution differences were found to be largely related to the hydrophobicity of the active ingredient and pH difference of the two media. This difference was even more evident under the condition where acetaminophen, sucrose, and Primojel were combined. The dissolution difference was therefore attributed to the depressed function of Primojel in the acidic medium, the stronger binding of sucrose, the hydrophobicity of the active ingredient and pH difference of the two media. Increasing the concentration of Primojel or incorporating the surfactant in the tablet can thus greatly decrease the dissolution difference between acidic and neutral media. PMID:9549889

  11. Solid and liquid media for isolating and cultivating acidophilic and acid-tolerant sulfate-reducing bacteria.

    Ňancucheo, Ivan; Rowe, Owen F; Hedrich, Sabrina; Johnson, D Barrie

    2016-05-01

    Growth media have been developed to facilitate the enrichment and isolation of acidophilic and acid-tolerant sulfate-reducing bacteria (aSRB) from environmental and industrial samples, and to allow their cultivation in vitro The main features of the 'standard' solid and liquid devised media are as follows: (i) use of glycerol rather than an aliphatic acid as electron donor; (ii) inclusion of stoichiometric concentrations of zinc ions to both buffer pH and to convert potentially harmful hydrogen sulphide produced by the aSRB to insoluble zinc sulphide; (iii) inclusion of Acidocella aromatica (an heterotrophic acidophile that does not metabolize glycerol or yeast extract) in the gel underlayer of double layered (overlay) solid media, to remove acetic acid produced by aSRB that incompletely oxidize glycerol and also aliphatic acids (mostly pyruvic) released by acid hydrolysis of the gelling agent used (agarose). Colonies of aSRB are readily distinguished from those of other anaerobes due to their deposition and accumulation of metal sulphide precipitates. Data presented illustrate the effectiveness of the overlay solid media described for isolating aSRB from acidic anaerobic sediments and low pH sulfidogenic bioreactors. PMID:27036143

  12. Correlations between different acidity forms in amorphous loamy soils of the tundra and taiga zones

    Shamrikova, E. V.; Sokolova, T. A.

    2013-05-01

    Pair correlation coefficients ( r) between the acidity parameters for the main genetic horizons of soddy-podzolic soils (SPSs), typical podzolic soils (TPSs), gley-podzolic soils (GPSs), and tundra surfacegley soils (TSGSs) have been calculated on the basis of a previously developed database. A significant direct linear correlation has been revealed between the pHwater and pHKCl values in the organic and eluvial horizons of each soil, but the degree of correlation decreased when going from the less acidic SPSs to the more acidic soils of other taxons. This could be related to the fact that, under strongly acid conditions, extra Al3+ was dissolved in the KCl solutions from complex compounds in the organic horizons and from Al hydroxide interlayers in the soil chlorites. No significant linear correlation has been found between the exchangeable acidity ( H exch) and the activity of the [H]+ ions in the KCl extract ( a(H+)KCl) calculated per unit of mass in the organic horizons of the SPSs, but it has been revealed in the organic horizons of the other soils because of the presence of the strongest organic acids in their KCl extracts. The high r values between the H exch and a(H+)KCl in all the soils of the taiga zones have been related to the common source and composition of the acidic components. The correlation between the exchangeable and total ( H tot) acidities in the organic horizons of the podzolic soils has been characterized by high r values because of the common source of the acidity: H+ and probably Al3+ ions located on the functional groups of organic acids. High r values between the H exch and a(H+)KCl have been observed in the mineral horizons of all the soils, because the Al3+ hydroxo complexes occurring on the surface and in the interlayer spaces of the clay minerals were sources of both acidity forms.

  13. The marker of cobalamin deficiency, plasma methylmalonic acid, correlates to plasma creatinine

    Hvas, A M; Juul, S; Gerdes, Lars Ulrik;

    2000-01-01

    : Records on 1689 patients who had their first plasma methylmalonic acid measurement during 1995 and 1996, and who had a simultaneous measurement of plasma cobalamins. Plasma creatinine values measured within a week of measurements of plasma methylmalonic acid and plasma cobalamins were available for 1255...... of the patients. MAIN OUTCOME MEASURES: Predictors of variation in plasma methylmalonic acid; plasma cobalamins, plasma creatinine, age and sex. RESULTS: Plasma methylmalonic acid was positively correlated with plasma creatinine, even for plasma creatinine within the normal range. These associations...... remained in a multiple regression analysis. For plasma cobalamins below 200 pmol L-1, there was a strong negative correlation between plasma methylmalonic acid and plasma cobalamins, whilst the association was weak for higher plasma cobalamin levels. Plasma methylmalonic acid increased and plasma...

  14. Anode material selection criteria for selective oxidation of inorganic compounds in nitric acid media

    Significant progress has been made since the 19606 in developing highly effective anode materials for electrochemical processes, The problem areas currently facing electrochemistry researchers include investigating new composite materials obtained by grafting or doping, improving fabrication techniques to extend the lifetime of the materials while maintaining their selectivity, studying their electrochemical properties and relating them to the material structure. Research on materials with high oxygen over-potentials-materials on which water oxidation is kinetically affected, and which open an electro-activity window on high potentials (2.0 VESH or greater) - has opened new avenues such as the use of various metallic oxide deposits. Two oxide classes were identified from a structural standpoint on the basis of their water oxidation properties: chemisorbed active oxygen anodes (e.g. PtOx, IrO2 or RuO2) and physi-sorbed active oxygen anodes (e.g. SnO2 or PbO2). Selective electrochemical generation of powerful oxidants between 1.4 and 2.0 VESH in concentrated nitric acid media is used in the context of the nuclear fuel cycle, and the potential advantages of new materials with a high oxygen over-potential-other than widely used platinum-have attracted attention. The relevant physical, chemical and electrochemical properties of such materials were therefore investigated to assess their selective oxidation performance. The study focused in particular on identifying the specific aspects of concentrated nitric acid media in the processes occurring at the electrode/solution interface, using linear and cyclic voltammetry, imposed-potential electrolysis and impedance spectroscopy. This approach allowed characterization of the electron charge transfer kinetics of the medium (nitric acid, compared with other acids such as methane sulfonic acid) and of the selected redox couple (Ag(II)/Ag(I) in this case). The tests covered a wide range of materials, including IrO2, SnO2, PbO2

  15. Culture media optimization of Porphyridium purpureum: production potential of biomass, total lipids, arachidonic and eicosapentaenoic acid.

    Kavitha, Mysore Doddaiah; Kathiresan, Shanmugam; Bhattacharya, Sila; Sarada, Ravi

    2016-05-01

    Porphyridium purpureum a red marine microalga is known for phycobiliproteins (PB), polyunsaturated fatty acids and sulphated exopolysaccharides. In the present study, effects of media constituents for the production of different polyunsaturated fatty acids from P. purpureum were considered using a response surface methodology (RSM). A second order polynomial was used to predict the response functions in terms of the independent variables such as the concentrations of sodium chloride, magnesium sulphate, sodium nitrate and potassium dihydrogen phosphate. The response functions were production of biomass yield, total lipid and polyunsaturated fatty acids like arachidonic acid (AA 20:4) and eicosapentaenoic acid (EPA 20:5). Results corroborated that maximum Biomass (0.95 gL(-1)) yield was at the concentrations of sodium chloride (14.89 gL(-1)), magnesium sulfate (3.93 gL(-1)) and sodium nitrate (0.96 gL(-1)) and potassium dihydrogen phosphate (0.09 gL(-1)). Optimum total lipid (17.9 % w/w) and EPA (34.6 % w/w) content was at the concentrations of sodium chloride (29.98 gL(-1)), magnesium sulfate (9.34 gL(-1)) and sodium nitrate (1.86 gL(-1)). Variation in concentration of potassium dihydrogen phosphate for both lipid (0.01gL(-1)) and EPA content (0.20 gL(-1)) was observed. The optimum conditions for biomass, total lipid, AA and EPA varied indicating their batch mode of growth and interaction effect of the salt. PMID:27407193

  16. Correlation of acid rain with the distributions of acid and alkaline elements in aerosols

    Acid rain often appeared both in Guiyang city of Guizhou province and Chongqing city of Sichuan province in the southwest of China. Aerosol samples in these two cities were collected by Andersen cascade sampler during the spring and autumn of 1995 respectively. The contents of 18 elements in the aerosol particles were analyzed by PIXE. The distributions of acid elements such as S, Cl and alkaline elements such as Ca, K in the aerosol samples from these two cities were calculated. The comparison of the distributions of acid and alkaline elements in the aerosols samples was made between these two cities and Beijing where no acid rain was found. The results showed that the acid rain in the southwest of China was caused by the dominant concentration of acid elements in the aerosol particles, which mainly resulted from the coal combustion and the lower alkalinity of soil in this area

  17. Review and assessment of technologies for the separation of strontium from alkaline and acidic media

    A literature survey has been conducted to identify and evaluate methods for the separation of strontium from acidic and alkaline media as applied to Hanford tank waste. The most promising methods of solvent extraction, precipitation, and ion exchange are described. The following criteria were used for evaluating the separation methods: Appreciable strontium removal must be demonstrated; Strontium selectivity over bulk components must be demonstrated; The method must show promise for evolving into a practical and fairly simple process; The process should be safe to operate; The method must be robust (i.e., capable of separating strontium from various waste types); Secondary waste generation must be minimized; and The method must show resistance to radiation damage. The methods discussed did not necessarily satisfy all of the above criteria; thus, key areas requiring further development are also given for each method. Less promising solvent extraction, precipitation, and ion exchange methods were also identified; areas for potential development are included in this report

  18. Radiation survival of two nalidixic acid resistant strains of Salmonella typhimurium in various media

    Radiation doses required for 90% inactivation, the D10 values, have been determined for two nalidixic acid-resistant strains of Salmonella typhimurium, NalR ATCC 13311, and K1-2B, in different media. The D10 values were 0.20, 0.57 and 0.53 kGy for the ATCC 13311 strain, and were 0.21, 0.4 and 0.32 kGy for the K1-2B strain, in phosphate buffer, in nutrient broth and on chicken drumsticks, respectively. Since these two strains have radiation sensitivity similar to several Salmonella serotypes reported in the literature, they are good indicator organisms for use in studies on the effect of irradiation on Salmonella in foods that might frequently be contaminated with such organisms. (author)

  19. Molecular dynamics study of solvation effects on acid dissociation in aprotic media

    Laria, D; Estrin, D A; Ciccotti, G; Laria, Daniel; Kapral, Raymond; Estrin, Dario; Ciccotti, Giovanni

    1996-01-01

    Acid ionization in aprotic media is studied using Molecular Dynamics techniques. In particular, models for HCl ionization in acetonitrile and dimethylsulfoxide are investigated. The proton is treated quantum mechanically using Feynman path integral methods and the remaining molecules are treated classically. Quantum effects are shown to be essential for the proper treatment of the ionization. The potential of mean force is computed as a function of the ion pair separation and the local solvent structure is examined. The computed dissociation constants in both solvents differ by several orders of magnitude which are in reasonable agreement with experimental results. Solvent separated ion pairs are found to exist in dimethylsulfoxide but not in acetonitrile. Dissociation mechanisms in small clusters are also investigated. Solvent separated ion pairs persist even in aggregates composed of rather few molecules, for instance, as few as thirty molecules. For smaller clusters or for large ion pair separations cluste...

  20. Morphology-dependent capacitive properties of three nanostructured polyanilines through interfacial polymerization in various acidic media

    Highlights: • Preparing three PANI nanostructures in HCl, H2SO4, and HNO3 reaction media during a slow interfacial polymerization. • Obtaining nanofibrous, nanogranular and hollow ball–like morphologies in the order of oxidizability of acids. • Demonstrating high specific capacitance, good rate performance and long cycle life of PANI nanofibers. - Abstract: Three nanostructured polyanilines (PANIs) were prepared by interfacial polymerization using different inorganic acids including HCl, H2SO4, and HNO3 as reaction media, respectively. The morphology-dependent structure and properties of as-prepared PANIs were characterized by means of scanning electron microscope, ultraviolet-visible spectra, Fourier transform infrared spectroscopy and X-ray diffraction patterns. Meanwhile, the electrochemical performance of the fabricated electrodes was evaluated by cyclic voltammetry, galvanostatic charge/discharge measurement, and electrochemical impedance spectroscopy. It is found that the reaction medium plays a vital role in deciding the final morphology and structure of product when a slow reaction rate occurred in interfacial polymerization. The as-prepared PANIs exhibited nanofibrous, nanogranular and hollow ball-like morphologies according to the order of the relative oxidizing ability of HCl < H2SO4 < HNO3, respectively. Furthermore, the capacitive properties of these composites as electrode materials highly depended not only on their morphologies but also on the conductivity, crystalline property and the inhibitory role of the lattice during the redox process, as well as the interparticle contact resistance. It is demonstrated that PANI nanofibers prepared in HCl medium exhibited high specific capacitance, good rate performance and long cycle life for the supercapacitor application

  1. Kinetic Analysis of Strains of Lactic Acid Bacteria and Acetic Acid Bacteria in Cocoa Pulp Simulation Media toward Development of a Starter Culture for Cocoa Bean Fermentation ▿

    Lefeber, Timothy; Janssens, Maarten; Camu, Nicholas; De Vuyst, Luc

    2010-01-01

    The composition of cocoa pulp simulation media (PSM) was optimized with species-specific strains of lactic acid bacteria (PSM-LAB) and acetic acid bacteria (PSM-AAB). Also, laboratory fermentations were carried out in PSM to investigate growth and metabolite production of strains of Lactobacillus plantarum and Lactobacillus fermentum and of Acetobacter pasteurianus isolated from Ghanaian cocoa bean heap fermentations, in view of the development of a defined starter culture. In a first step, a...

  2. Noble metal catalyzed hydrogen generation from formic acid in nitrite-containing simulated nuclear waste media

    The Hanford Waste Vitrification Plant (HWVP) is being designed by the U.S. Department of Energy to immobilize high-level nuclear waste. Simulants for the HWVP feed containing the major nonradioactive components Al, Cd, Fe, Mn, Nd, Ni, Si, Zr, Na, CO32-, NO3- and NO2- were used as media to evaluate the stability of formic acid towards hydrogen evolution by the reaction HCO2H→H2+/CO2 catalyzed by the noble metals Ru, Rh, and/or Pd found in significant quantities in uranium fission products. Small-scale experiments using 40-50 mL of feed simulant in closed glass reactors (250-550 mL total volume) at 80-100 degree C were used to study the effect of nitrite and nitrate ion on the catalytic activities of the noble metals for formic acid decomposition. Reactions were monitored using gas chromatography to analyze the CO2, H2, NO, and N2O in the gas phase as a function of time. Rhodium, which was introduced as soluble RhCl3.3H2O, was found to be the most active catalyst for hydrogen generation from formic acid above nearly 80 degree C in the presence of nitrite ion in accord with earlier observations. The apparent homogeneous nature of the nitrite-promoted Rh-catalyzed formic acid decomposition is consistent with the approximate pseudo-first-order dependence of the hydrogen production rate on Rh concentration. 24 refs., 7 figs., 2 tabs

  3. Erythrocyte Sialic Acid Content during Aging in Humans: Correlation with Markers of Oxidative Stress

    Mehdi, Mohammad Murtaza; Singh, Prabhakar; Rizvi, Syed Ibrahim

    2012-01-01

    Sialic acids are substituted neuraminic acid derivatives which are typically found at the outermost end of glycan chains on the membrane in all cell types. The role of erythrocyte membrane sialic acids during aging has been established however the relationship between sialic acid and oxidative stress is not fully understood. The present work was undertaken to analyze the relationship between erythrocyte membrane sialic acid with its plasma level, membrane and plasma lipid hydroperoxide levels and plasma total antioxidant capacity. Results show that sialic acid content decreases significantly (P < 0.001) in RBC membrane (r = −0.901) and increases in plasma (r = 0.860) as a function of age in humans. Lipid peroxidation measured in the form of hydroperoxides increases significantly (P < 0.001) in plasma (r = 0.830) and RBC membranes (r = 0.875) with age in humans. The Trolox Equivalent Total Antioxidant Capacity (TETAC) of plasma was found to be significantly decreased (P < 0.001, r = −0.844). We observe significant correlations between decrease of erythrocyte membrane sialic acid and plasma lipid hydroperoxide and TETAC. Based on the observed correlations, we hypothesize that increase in oxidative stress during aging may influence the sialic acid decomposition from membrane thereby altering the membrane configuration affecting many enzymatic and transporter activities. Considering the importance of plasma sialic acid as a diagnostic parameter, it is important to establish age-dependent reference. PMID:22377734

  4. Studies on rapid ion-exchange separation of the transplutonium elements with mineral acid-methanol mixed media

    In order to study properties of short-lived transplutonium nuclides synthesized by heavy-ion bombardment, three methods for rapid separation of tri-valent transplutonium elements by ion-exchange chromatography with mineral acid-methanol mixed media at elevated temperature were investigated. The first separation method was anion-exchange chromatography with nitric acid-methanol mixed media. The second method was anion-exchange choromatography with dilute hydrochloric acid-methanol mixed media. The third method was improved cation-exchange chromatography with single-column operation using the mixed media of hydrochloric acid and methanol. The separation methods developed were found applicable to studies on synthesis of the trans-plutonium nuclides, 250Fm (T1/2:30 min), 244,245,246Cf (T1/2:20 min, 46 min and 35.7 h, respectively) from the 16O + 238U and12C + 242Pu reactions, and on the decay property of 245Cf. Attempts to search for new actinide nuclides, such as 240U and neutron deficient nuclides of Am, Cm and Bk, were made by a quick purification. The separation system was also applied to the rapid and effective separation of Nd, Am and Cm from spent nuclear fuel samples, for burn-up determination. (J.P.N.) 242 refs

  5. Noble metal-free bifunctional oxygen evolution and oxygen reduction acidic media electro-catalysts

    Patel, Prasad Prakash; Datta, Moni Kanchan; Velikokhatnyi, Oleg I.; Kuruba, Ramalinga; Damodaran, Krishnan; Jampani, Prashanth; Gattu, Bharat; Shanthi, Pavithra Murugavel; Damle, Sameer S.; Kumta, Prashant N.

    2016-07-01

    Identification of low cost, highly active, durable completely noble metal-free electro-catalyst for oxygen reduction reaction (ORR) in proton exchange membrane (PEM) fuel cells, oxygen evolution reaction (OER) in PEM based water electrolysis and metal air batteries remains one of the major unfulfilled scientific and technological challenges of PEM based acid mediated electro-catalysts. In contrast, several non-noble metals based electro-catalysts have been identified for alkaline and neutral medium water electrolysis and fuel cells. Herein we report for the very first time, F doped Cu1.5Mn1.5O4, identified by exploiting theoretical first principles calculations for ORR and OER in PEM based systems. The identified novel noble metal-free electro-catalyst showed similar onset potential (1.43 V for OER and 1 V for ORR vs RHE) to that of IrO2 and Pt/C, respectively. The system also displayed excellent electrochemical activity comparable to IrO2 for OER and Pt/C for ORR, respectively, along with remarkable long term stability for 6000 cycles in acidic media validating theory, while also displaying superior methanol tolerance and yielding recommended power densities in full cell configurations.

  6. Mechanisms of the rapid dissolution of plutonium dioxide in acidic media under oxidizing or reducing conditions

    Until recently plutonium dioxide was known to be among the metallic oxides most difficult to dissolve. This property is understandable given the free energy of the dissolution reaction (ΔG0) in acidic noncomplexing media (ΔG0 = 32.04 kJ/mol). Thermodynamic calculations predict that PuO2 will dissolve under oxidizing or reducing conditions. The oxidizing dissolution, leading to Pu(VI) ion in solution, is easy to perform with a strong oxidant like Ag(II). The mechanism of the oxidizing dissolution of PuO2 was investigated by using carbon paste electrochemistry (CPE) and 18 O labeling. PuO2 can also be dissolved in acidic solution if the redox potential of the mixture is low (e.g., Cr2+, V2+, or U3+ as reducing agents). The kinetics of the heterogeneous reducing dissolution of PuO2 with Cr2+ were investigated and the reaction mechanism was determined by 18 O labeling. All the results will be presented and discussed in the context of minimizing the amount of plutonium-contaminated solid wastes in the nuclear fuel cycle. 9 figs., 17 refs

  7. Oxidation of hydrogen peroxide by [NiIII(cyclam)]3+ in aqueous acidic media

    Sankaran Anuradha; Venkatapuram Ramanujam Vijayaraghavan

    2013-09-01

    The kinetics of oxidation of H2O2 by [NiIII(cyclam)]3+, [NiIIIL1], was studied in aqueous acidic media at 25°C and I = 0.5M (NaClO4). The [NiIIIL1] to [NiIIL1] reduction was found to be fast in the presence of Cu(II) ion than the oxidation of the cyclam ligand by ·OH. The rate constant showed an inverse acid dependence on H+ ion at the pH range 1-1.5. The presence of sulphate retards the reaction. Macrocylic ligand oxidation was followed spectrophotometrically by examining the oxidation of nickel(II) complexes of macrocyclic ligands such as 1,8-bis(2-hydroxyethyl)-1,3,6,8,10,13-hexaazacyclotetradecane (L2), -5,7,7,12,14,14-hexamethyl-1,4,8,11-tetraazacyclotetradecane (L3), rac-Me6[14]-4,11-dieneN4 (L4) by reaction with hydrogen peroxide. The rate constant for the cross reaction is discussed in terms of Marcus relationship.

  8. Inhibitive action of some plant extracts on the corrosion of steel in acidic media

    The effect of extracts of Chamomile (Chamaemelum mixtum L.), Halfabar (Cymbopogon proximus), Black cumin (Nigella sativa L.), and Kidney bean (Phaseolus vulgaris L.) plants on the corrosion of steel in aqueous 1 M sulphuric acid were investigated by electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization techniques. EIS measurements showed that the dissolution process of steel occurs under activation control. Potentiodynamic polarization curves indicated that the plant extracts behave as mixed-type inhibitors. The corrosion rates of steel and the inhibition efficiencies of the extracts were calculated. The results obtained show that the extract solution of the plant could serve as an effective inhibitor for the corrosion of steel in sulphuric acid media. Inhibition was found to increase with increasing concentration of the plant extract up to a critical concentration. The inhibitive actions of plant extracts are discussed on the basis of adsorption of stable complex at the steel surface. Theoretical fitting of different isotherms, Langmuir, Flory-Huggins, and the kinetic-thermodynamic model, were tested to clarify the nature of adsorption

  9. Noble metal-free bifunctional oxygen evolution and oxygen reduction acidic media electro-catalysts.

    Patel, Prasad Prakash; Datta, Moni Kanchan; Velikokhatnyi, Oleg I; Kuruba, Ramalinga; Damodaran, Krishnan; Jampani, Prashanth; Gattu, Bharat; Shanthi, Pavithra Murugavel; Damle, Sameer S; Kumta, Prashant N

    2016-01-01

    Identification of low cost, highly active, durable completely noble metal-free electro-catalyst for oxygen reduction reaction (ORR) in proton exchange membrane (PEM) fuel cells, oxygen evolution reaction (OER) in PEM based water electrolysis and metal air batteries remains one of the major unfulfilled scientific and technological challenges of PEM based acid mediated electro-catalysts. In contrast, several non-noble metals based electro-catalysts have been identified for alkaline and neutral medium water electrolysis and fuel cells. Herein we report for the very first time, F doped Cu1.5Mn1.5O4, identified by exploiting theoretical first principles calculations for ORR and OER in PEM based systems. The identified novel noble metal-free electro-catalyst showed similar onset potential (1.43 V for OER and 1 V for ORR vs RHE) to that of IrO2 and Pt/C, respectively. The system also displayed excellent electrochemical activity comparable to IrO2 for OER and Pt/C for ORR, respectively, along with remarkable long term stability for 6000 cycles in acidic media validating theory, while also displaying superior methanol tolerance and yielding recommended power densities in full cell configurations. PMID:27380719

  10. Inhibitive action of some plant extracts on the corrosion of steel in acidic media

    Abdel-Gaber, A.M. [Department of Chemistry, Faculty of Science, Alexandria University, Ibrahimia, P.O. Box 426, Alexandria 21321 (Egypt)]. E-mail: ashrafmoustafa@yahoo.com; Abd-El-Nabey, B.A. [Department of Chemistry, Faculty of Science, Alexandria University, Ibrahimia, P.O. Box 426, Alexandria 21321 (Egypt); Sidahmed, I.M. [Department of Chemistry, Faculty of Science, Alexandria University, Ibrahimia, P.O. Box 426, Alexandria 21321 (Egypt); El-Zayady, A.M. [Department of Chemistry, Faculty of Science, Alexandria University, Ibrahimia, P.O. Box 426, Alexandria 21321 (Egypt); Saadawy, M. [Department of Chemistry, Faculty of Science, Alexandria University, Ibrahimia, P.O. Box 426, Alexandria 21321 (Egypt)

    2006-09-15

    The effect of extracts of Chamomile (Chamaemelum mixtum L.), Halfabar (Cymbopogon proximus), Black cumin (Nigella sativa L.), and Kidney bean (Phaseolus vulgaris L.) plants on the corrosion of steel in aqueous 1 M sulphuric acid were investigated by electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization techniques. EIS measurements showed that the dissolution process of steel occurs under activation control. Potentiodynamic polarization curves indicated that the plant extracts behave as mixed-type inhibitors. The corrosion rates of steel and the inhibition efficiencies of the extracts were calculated. The results obtained show that the extract solution of the plant could serve as an effective inhibitor for the corrosion of steel in sulphuric acid media. Inhibition was found to increase with increasing concentration of the plant extract up to a critical concentration. The inhibitive actions of plant extracts are discussed on the basis of adsorption of stable complex at the steel surface. Theoretical fitting of different isotherms, Langmuir, Flory-Huggins, and the kinetic-thermodynamic model, were tested to clarify the nature of adsorption.

  11. Mechanisms of the rapid dissolution of plutonium dioxide in acidic media under oxidizing or reducing conditions

    Until recently plutonium dioxide was known to be among the metallic oxides most difficult to dissolve. This property is understandable given the free energy of the dissolution reaction (ΔG0) in acidic noncomplexing media (ΔG0 = 32.04 kJ/mol). Thermodynamic calculations predict that PuO2 will dissolve under oxidizing or reducing conditions. The oxidizing dissolution, leading to Pu(VI) ion in solution, is easy to perform with a strong oxidant like Ag(II). The mechanism of the oxidizing dissolution of PuO2 was investigated by using carbon paste electrochemistry (CPE) and 18O labeling. PuO2 can also be dissolved in acidic solution if the redox potential of the mixture is low (e.g., Cr2+, V2+, or U3+ as reducing agents). The kinetics of the heterogeneous reducing dissolution of PuO2 with Cr2+ were investigated and the reaction mechanism was determined by 18O labeling. In this paper all the results are presented and discussed in the context of minimizing the amount of plutonium-contaminated solid wastes in the nuclear fuel cycle

  12. Noble metal-free bifunctional oxygen evolution and oxygen reduction acidic media electro-catalysts

    Patel, Prasad Prakash; Datta, Moni Kanchan; Velikokhatnyi, Oleg I.; Kuruba, Ramalinga; Damodaran, Krishnan; Jampani, Prashanth; Gattu, Bharat; Shanthi, Pavithra Murugavel; Damle, Sameer S.; Kumta, Prashant N.

    2016-01-01

    Identification of low cost, highly active, durable completely noble metal-free electro-catalyst for oxygen reduction reaction (ORR) in proton exchange membrane (PEM) fuel cells, oxygen evolution reaction (OER) in PEM based water electrolysis and metal air batteries remains one of the major unfulfilled scientific and technological challenges of PEM based acid mediated electro-catalysts. In contrast, several non-noble metals based electro-catalysts have been identified for alkaline and neutral medium water electrolysis and fuel cells. Herein we report for the very first time, F doped Cu1.5Mn1.5O4, identified by exploiting theoretical first principles calculations for ORR and OER in PEM based systems. The identified novel noble metal-free electro-catalyst showed similar onset potential (1.43 V for OER and 1 V for ORR vs RHE) to that of IrO2 and Pt/C, respectively. The system also displayed excellent electrochemical activity comparable to IrO2 for OER and Pt/C for ORR, respectively, along with remarkable long term stability for 6000 cycles in acidic media validating theory, while also displaying superior methanol tolerance and yielding recommended power densities in full cell configurations. PMID:27380719

  13. Deficient liver biosynthesis of docosahexaenoic acid correlates with cognitive impairment in Alzheimer's disease.

    Giuseppe Astarita

    Full Text Available Reduced brain levels of docosahexaenoic acid (C22:6n-3, a neurotrophic and neuroprotective fatty acid, may contribute to cognitive decline in Alzheimer's disease. Here, we investigated whether the liver enzyme system that provides docosahexaenoic acid to the brain is dysfunctional in this disease. Docosahexaenoic acid levels were reduced in temporal cortex, mid-frontal cortex and cerebellum of subjects with Alzheimer's disease, compared to control subjects (P  =  0.007. Mini Mental State Examination (MMSE scores positively correlated with docosahexaenoic/α-linolenic ratios in temporal cortex (P =  0.005 and mid-frontal cortex (P  =  0.018, but not cerebellum. Similarly, liver docosahexaenoic acid content was lower in Alzheimer's disease patients than control subjects (P  =  0.011. Liver docosahexaenoic/α-linolenic ratios correlated positively with MMSE scores (r  =  0.78; P<0.0001, and negatively with global deterioration scale grades (P  =  0.013. Docosahexaenoic acid precursors, including tetracosahexaenoic acid (C24:6n-3, were elevated in liver of Alzheimer's disease patients (P  =  0.041, whereas expression of peroxisomal d-bifunctional protein, which catalyzes the conversion of tetracosahexaenoic acid into docosahexaenoic acid, was reduced (P  = 0.048. Other genes involved in docosahexaenoic acid metabolism were not affected. The results indicate that a deficit in d-bifunctional protein activity impairs docosahexaenoic acid biosynthesis in liver of Alzheimer's disease patients, lessening the flux of this neuroprotective fatty acid to the brain.

  14. Incorporation of alpha-Ketoglutaric Acid as a Fixed Bed Scrubber Media for the Neutralization of Hydrazine Family Hypergolic Fuels

    DeVor, R. W.; Santiago-Maldonado, E.; Parkerson, J. K.

    2010-01-01

    A candidate scrubber media, alpha-ketoglutaric acid (aKGA) adsorbed onto a silica-based substrate was examined as a potential alternative to the hydrazine-family hypergolic fuel neutralization techniques currently utilized at NASA/Kennedy Space Center (KSC). Helvenson et. al. has indicated that aKGA will react with hydrazines to produce non-hazardous, possibly biodegradable products. Furthermore, the authors have previously tested and demonstrated the use of aKGA aqueous solutions as a replacement neutralizing agent for citric acid, which is currently used as a scrubbing agent in liquid scrubbers at KSC. Specific properties examined include reaction efficiency, the loading capacity of aKGA onto various silica substrates, and the comparison of aKGA media performance to that of the citric acid vapor scrubber systems at KSC and a commercial vapor scrubber media. Preliminary investigations showed hydrophobic aerogel particles to be an ideal substrate for the deposition of the aKGA. Current studies have shown that the laboratory produced aKGA-Aerogel absorbent media are more efficient and cost effective than a commercially available fixed bed scrubber media, although much less cost effective than liquid-based citric acid scrubbers (although possibly safer and less labor intensive). A comparison of all three alternative scrubber technologies (liquid aKGA, solid-phase aKGA, and commercially available sorbent materials) is given considering both hypergolic neutralization capabilities and relative costs (as compared to the current citric acid scrubbing technology in use at NASA/KSC).

  15. HIV testing among social media-using Peruvian men who have sex with men: correlates and social context.

    Krueger, Evan A; Chiu, ChingChe J; Menacho, Luis A; Young, Sean D

    2016-10-01

    HIV remains concentrated among men who have sex with men (MSM) in Peru, and homophobia and AIDS-related stigmas have kept the epidemic difficult to address. Gay self-identity has been associated with increased HIV testing, though this relationship has not been examined extensively. Social media use has been rapidly increasing in Peru, yet little is known about MSM social media users in Peru. This study sought to investigate the demographic, behavioral, and stigma-related factors associated with HIV testing among social media-using Peruvian MSM. Five hundred and fifty-six MSM from Lima and surrounding areas were recruited from social networking websites to complete a survey on their sexual risk behaviors. We examined the demographic and social correlates of HIV testing behavior among this sample. Younger age and non-gay identity were significantly associated with lower likelihood of getting tested in univariate analysis. After controlling for key behaviors and AIDS-related stigma, younger age remained significantly associated with decreased testing. Participants who engaged in discussions online about HIV testing were more likely to get tested, while AIDS-related stigma presented a significant barrier to testing. Stigma severity also varied significantly by sexual identity. Youth appear to be significantly less likely than older individuals to test for HIV. Among Peruvian MSM, AIDS-related stigma remains a strong predictor of willingness to get tested. Social media-based intervention work targeting Peruvian youth should encourage discussion around HIV testing, and must also address AIDS-related stigma. PMID:27140820

  16. Intima-media thickness evaluation by B-mode ultrasound: Correlation with blood pressure levels and cardiac structures

    F.L. Plavnik

    2000-01-01

    Full Text Available The aim of this study was to analyze the thickness of the intima-media complex (IMC using a noninvasive method. The carotid and femoral common arteries were evaluated by noninvasive B-mode ultrasound in 63 normotensive and in 52 hypertensive subjects and the thickness of the IMC was tested for correlation with blood pressure, cardiac structures and several clinical and biological parameters. The IMC was thicker in hypertensive than in normotensive subjects (0.67 ± 0.13 and 0.62 ± 0.16 vs 0.54 ± 0.09 and 0.52 ± 0.11 mm, respectively, P<0.0001. In normotensive patients, the simple linear regression showed significant correlations between IMC and age, body mass index and 24-h systolic blood pressure for both the carotid and femoral arteries. In hypertensives the carotid IMC was correlated with age and 24-h systolic blood pressure while femoral IMC was correlated only with 24-h diastolic blood pressure. Forward stepwise regression showed that age, body mass index and 24-h systolic blood pressure influenced the carotid IMC relationship (r2 = 0.39 in normotensives. On the other hand, the femoral IMC relationship was influenced by 24-h systolic blood pressure and age (r2 = 0.40. In hypertensives, age and 24-h systolic blood pressure were the most important determinants of carotid IMC (r2 = 0.37, while femoral IMC was influenced only by 24-h diastolic blood pressure (r2 = 0.10. There was an association between carotid IMC and echocardiographic findings in normotensives, while in hypertensives only the left posterior wall and interventricular septum were associated with femoral IMC. We conclude that age and blood pressure influence the intima-media thickness, while echocardiographic changes are associated with the IMC.

  17. Lewis Acid Pairs for the Activation of Biomass-derived Oxygenates in Aqueous Media

    Roman, Yuriy [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States)

    2015-09-14

    The objective of this project is to understand the mechanistic aspects behind the cooperative activation of oxygenates by catalytic pairs in aqueous media. Specifically, we will investigate how the reactivity of a solid Lewis acid can be modulated by pairing the active site with other catalytic sites at the molecular level, with the ultimate goal of enhancing activation of targeted functional groups. Although unusual catalytic properties have been attributed to the cooperative effects promoted by such catalytic pairs, virtually no studies exist detailing the use heterogeneous water-tolerant Lewis pairs. A main goal of this work is to devise rational pathways for the synthesis of porous heterogeneous catalysts featuring isolated Lewis pairs that are active in the transformation of biomass-derived oxygenates in the presence of bulk water. Achieving this technical goal will require closely linking advanced synthesis techniques; detailed kinetic and mechanistic investigations; strict thermodynamic arguments; and comprehensive characterization studies of both materials and reaction intermediates. For the last performance period (2014-2015), two technical aims were pursued: 1) C-C coupling using Lewis acid and base pairs in Lewis acidic zeolites. Tin-, zirconium-, and hafnium containing zeolites (e.g., Sn-, Zr-, and Hf-Beta) are versatile solid Lewis acids that selectively activate carbonyl functional groups. In this aim, we demonstrate that these zeolites catalyze the cross-aldol condensation of aromatic aldehydes with acetone under mild reaction conditions with near quantitative yields. NMR studies with isotopically labeled molecules confirm that acid-base pairs in the Si-O-M framework ensemble promote soft enolization through α-proton abstraction. The Lewis acidic zeolites maintain activity in the presence of water and, unlike traditional base catalysts, in acidic solutions. 2) One-pot synthesis of MWW zeolite nanosheets for activation of bulky substrates. Through

  18. Using geometry to manipulate long-range correlation of light inside disordered media

    Sarma, Raktim; Neupane, Pauf; Cao, Hui

    2015-01-01

    We demonstrate experimentally that long-range intensity correlation for light propagating inside random photonic waveguides can be modified by changing the shape of the waveguide. The functional form of spatial correlation is no longer universal in the regime of diffusive transport and becomes shape-dependent due to the non-local nature of wave propagation. The spatial dependence of the correlation may be asymmetric for light incident from opposite ends of the waveguide. This work opens the door to control non-local effects in mesoscopic transport of waves by manipulating the geometry of random systems.

  19. Correlation characteristics of optical coherence tomography images of turbid media with statistically inhomogeneous optical parameters

    Noisy structure of optical coherence tomography (OCT) images of turbid medium contains information about spatial variations of its optical parameters. We propose analytical model of statistical characteristics of OCT signal fluctuations from turbid medium with spatially inhomogeneous coefficients of absorption and backscattering. Analytically predicted correlation characteristics of OCT signal from spatially inhomogeneous medium are in good agreement with the results of correlation analysis of OCT images of different biological tissues. The proposed model can be efficiently applied for quantitative evaluation of statistical properties of absorption and backscattering fluctuations basing on correlation characteristics of OCT images.

  20. Production of Antilisterial Bacteriocins from Lactic Acid Bacteria in Dairy-Based Media: A Comparative Study.

    Ünlü, Gülhan; Nielsen, Barbara; Ionita, Claudia

    2015-12-01

    One hundred and eight strains of lactic acid bacteria (LAB) were screened for bacteriocin production by the modified deferred antagonism and agar well diffusion methods. When the modified deferred antagonism method was employed, 82 LAB strains showed inhibitory action against Listeria monocytogenes v7 ½a, whereas 26 LAB strains expressed no inhibition. Only 12 LAB strains exhibited inhibitory activity when the agar well diffusion method was used, 11 of which had been previously recognized as bacteriocin production positive (Bac(+)). Lactobacillus viridescens NRRL B-1951 was determined, for the first time, to produce an inhibitory compound with a proteinaceous nature. The inhibitory activity was observed in the presence of lipase, α-chymotrypsin, and trypsin, but no inhibition zone could be detected in the presence of proteinase K, indicating the proteinaceous nature of the inhibitory compound. The inhibitory compound was active against Lact. sake ATCC 15521 and Lact. plantarum NCDO 995. Bacteriocin production by the Bac(+) LAB strains was assessed in Lactobacillus MRS Broth as well as in dairy-based media such as nonfat milk, demineralized whey powder, and cheddar cheese whey supplemented with complex nutrient sources that are rich in nitrogen. Lact. sake ATCC 15521 and L. monocytogenes CWD 1002, CWD 1092, CWD 1157, CWD 1198, and v7 ½a were used as indicators. The inhibitory activities of the bacteriocins varied depending on the indicator strains and the growth media used. The LAB indicator strains were found to be more sensitive to inhibition by bacteriocins when compared to the listerial indicator strains. Among the listerial indicators, L. monocytogenes CWD 1002 and CWD 1198 were the most sensitive strains to the bacteriocins investigated in this study. Media composition had a significant influence on bacteriocin production and activity. When compared to demineralized whey powder medium and cheddar cheese whey medium supplemented with whey protein concentrate

  1. Stability of Monitoring Weak Changes in Multiply Scattering Media with Ambient Noise Correlation: Laboratory Experiments

    Hadziioannou, Céline; Coutant, Olivier; Roux, Philippe; Campillo, Michel

    2009-01-01

    Previous studies have shown that small changes can be monitored in a scattering medium by observing phase shifts in the coda. Passive monitoring of weak changes through ambient noise correlation has already been applied to seismology, acoustics and engineering. Usually, this is done under the assumption that a properly reconstructed Green function as well as stable background noise sources are necessary. In order to further develop this monitoring technique, a laboratory experiment was performed in the 2.5MHz range in a gel with scattering inclusions, comparing an active (pulse-echo) form of monitoring to a passive (correlation) one. Present results show that temperature changes in the medium can be observed even if the Green function (GF) of the medium is not reconstructed. Moreover, this article establishes that the GF reconstruction in the correlations is not a necessary condition: the only condition to monitoring with correlation (passive experiment) is the relative stability of the background noise struc...

  2. DUST SCATTERING IN TURBULENT MEDIA: CORRELATION BETWEEN THE SCATTERED LIGHT AND DUST COLUMN DENSITY

    Radiative transfer models in a spherical, turbulent interstellar medium (ISM), in which the photon source is situated at the center, are calculated to investigate the correlation between the scattered light and the dust column density. The medium is modeled using fractional Brownian motion structures that are appropriate for turbulent ISM. The correlation plot between the scattered light and optical depth shows substantial scatter and deviation from simple proportionality. It was also found that the overall density contrast is smoothed out in scattered light. In other words, there is an enhancement of the dust-scattered flux in low-density regions, while the scattered flux is suppressed in high-density regions. The correlation becomes less significant as the scattering becomes closer to being isotropic and the medium becomes more turbulent. Therefore, the scattered light observed in near-infrared wavelengths would show much weaker correlation than the observations in optical and ultraviolet wavelengths. We also find that the correlation plot between scattered lights at two different wavelengths shows a tighter correlation than that of the scattered light versus the optical depth

  3. Determination and structural correlation of the pKa values of p-substituted trans-2,3-epoxy-4-oxo-4-phenylbutanoic acids

    I. JURANIC

    2000-11-01

    Full Text Available The pKa values for a series of eight p-substituted trans-2,3-epoxy-4-phenyl butanoic acids (p-substituted trans-b-aroylepoxyacrylic acids have been determined potentiometrically in aqueous media at 25°C at an ionic strength of 0.1 mol/dm3 (NaCl. The transmission of polar effects from the substituents on the phenyl nucleus to the carboxylic group through the side chain involving a carbonyl group and an epoxide ring was investigated. The pKa values were correlated with structure using the Hammett, Taft and Yukawa-Tsuno approaches. The Hammett r constant (0.34 was compared with analogue values for structurally similar acids.

  4. Hyaluronic acid production by Streptococcus zooepidemicus in marine by-products media from mussel processing wastewaters and tuna peptone viscera

    Murado Miguel A

    2010-06-01

    Full Text Available Abstract Background Hyaluronic acid is one of the biopolymers most commonly used by the pharmaceutical industry. Thus, there is an increasing number of recent works that deal with the production of microbial hyaluronic acid. Different properties and characteristics of the fermentation process have been extensively optimised; however, new carbon and protein sources obtained from by-products or cheap substrates have not yet been studied. Results Mussel processing wastewater (MPW was used as a sugar source and tuna peptone (TP from viscera residue as a protein substrate for the production of hyaluronic acid (HA, biomass and lactic acid (LA by Streptococcus zooepidemicus in batch fermentation. Commercial medium formulated with glucose and tryptone was used as the control. The parametric estimations obtained from logistic equations and maintenance energy model utilized for modelling experimental data were compared in commercial and low-cost media. Complete residual media achieved high production (3.67, 2.46 and 30.83 g l-1 of biomass, HA and LA respectively and a high molecular weight of HA (approximately 2500 kDa. A simple economic analysis highlighted the potential viability of this marine media for reducing the production costs by more than 50%. Conclusions The experimental data and mathematical descriptions reported in this article demonstrate the potential of media formulated with MPW and TP to be used as substrates for HA production by S. zooepidemicus. Furthermore, the proposed equations accurately simulated the experimental profiles and generated a set of interesting parameters that can be used to compare the different bacterial cultures. To the best of our knowledge, this is the first work in which a culture media formed by marine by-products has been successfully used for microbial HA production.

  5. Universal correlations between shocks in the ground state of elastic interfaces in disordered media.

    Thiery, Thimothée; Le Doussal, Pierre; Wiese, Kay Jörg

    2016-07-01

    The ground state of an elastic interface in a disordered medium undergoes collective jumps upon variation of external parameters. These mesoscopic jumps are called shocks, or static avalanches. Submitting the interface to a parabolic potential centered at w, we study the avalanches which occur as w is varied. We are interested in the correlations between the avalanche sizes S_{1} and S_{2} occurring at positions w_{1} and w_{2}. Using the functional renormalization group (FRG), we show that correlations exist for realistic interface models below their upper critical dimension. Notably, the connected moment 〈S_{1}S_{2}〉^{c} is up to a prefactor exactly the renormalized disorder correlator, itself a function of |w_{2}-w_{1}|. The latter is the universal function at the center of the FRG; hence, correlations between shocks are universal as well. All moments and the full joint probability distribution are computed to first nontrivial order in an ε expansion below the upper critical dimension. To quantify the local nature of the coupling between avalanches, we calculate the correlations of their local jumps. We finally test our predictions against simulations of a particle in random-bond and random-force disorder, with surprisingly good agreement. PMID:27575080

  6. Lipase in biphasic alginate beads as a biocatalyst for esterification of butyric acid and butanol in aqueous media.

    Ng, Choong Hey; Yang, Kun-Lin

    2016-01-01

    Esterification of organic acids and alcohols in aqueous media is very inefficient due to thermodynamic constraints. However, fermentation processes used to produce organic acids and alcohols are often conducted in aqueous media. To produce esters in aqueous media, biphasic alginate beads with immobilized lipase are developed for in situ esterification of butanol and butyric acid. The biphasic beads contain a solid matrix of calcium alginate and hexadecane together with 5 mg/mL of lipase as the biocatalyst. Hexadecane in the biphasic beads serves as an organic phase to facilitate the esterification reaction. Under optimized conditions, the beads are able to catalyze the production of 0.16 mmol of butyl butyrate from 0.5 mmol of butyric acid and 1.5 mmol of butanol. In contrast, when monophasic beads (without hexadecane) are used, only trace amount of butyl butyrate is produced. One main application of biphasic beads is in simultaneous fermentation and esterification (SFE) because the organic phase inside the beads is very stable and does not leach out into the culture medium. SFE is successfully conducted with an esterification yield of 6.32% using biphasic beads containing iso-octane even though the solvent is proven toxic to the butanol-producing Clostridium spp. PMID:26672465

  7. Glycolic Acid Ethoxylate Lauryl Ether Performance as Drag Reducing Agent in Aqueous Media Flow in Pipelines

    H.A. Abdul Bari

    2008-01-01

    Full Text Available In this study, Glycolic Acid Ethoxylate Lauryl Ether (GAELE anionic surfactant performance as drag reducing agent in aqueous media flow in pipelines was investigated. Testing section length L to pipe diameter D ration (L/D, addive concentration and solution flow rates were the major variables to be investigated in the present study. All the experimental study was carried in a build up experimental rig with three pipe diameters (0.0127, 0.0254 and 0.0381 m inside diameter. The experimental results showed that the (GAELE anionic can perform as a good drag reducing agent with maximum percentage drag reduction of 73% obtained in 39.37 of L/D for 600 ppm of solution. In 26.24 L/D the highest drag reduction obtained was 53% for 600 ppm of solution. The drag reduction increases corresponding with the increasing of L/D. The setup point where the effect of the drag reducer starts to take action was at Reynolds Number Re of 21000 in L/D equals to 39.37 and at Re = 30000 in 26.24 of L/D. From experimental results, it was shown that the critical wall shear stress occur at Re = 25000 in L/D = 39.37 and at Re = 35000 in L/D = 26.24.

  8. Electro-Oxidation of Concentrated Ce(Ⅲ) at Carbon Felt Anode in Nitric Acid Media

    2006-01-01

    Electro-oxidation of Ce( Ⅲ) to Ce( Ⅳ ) in parallel plate flow type electrolyzer divided with cation exchange membrane was carried out in nitric acid media at carbon felt anode under galvanostatic conditions. Carbon felt was used as an anode for its high specific surface area and high oxygen evolution overpotential. Pt coated Ti plates were used as cathcurrent efficiency (92%) until about 80% of Ce( Ⅲ) was oxidized. Then, oxygen evolution, accompanied by terminal voltage jump, took place, lowering current efficiency. Ce( Ⅲ ) was oxidized up to 90% with current efficiency of 62%. In this mode, strong carbon felt anode oxidation was observed. The wear out of carbon felt was 46% in six consequent runs (6 h of operation). After each run, carbon felt surface had to be renewed with slightly alkaline solution to remove carbon oxidation products and ensure regular operational conditions. When anode surface was blocked, oxygen evolution took place from the beginning of electrolysis due to higher actual current density. The wear out of carbon felt anode could be minimized by means of oxygen evolution prevention. In the case when electrolysis had been stopped before oxygen evolution started (at Ce( Ⅳ ) conversion of about 80% ), the wear out of anode was less than 2% during 6 consequent runs (4 h of operation).

  9. Determination and correlation of cefuroxime acid solubility in (acetonitrile + water) mixtures

    Highlights: • The solubility of cefuroxime acid in different solvents was experimentally determined. • The experimental solubility data were correlated by three models. • The AIC was used to select the best solubility model. • The thermodynamic properties of cefuroxime acid in solution were obtained. - Abstract: The solubility of cefuroxime acid in (acetonitrile + water) mixtures was experimentally determined at temperatures from (278.15 to 313.15) K by using a dynamic method at atmospheric pressure. The solubility increased with the increasing of temperature, and it reached the maximum at acetonitrile molar fraction of 0.713 at constant temperature. The experimental solubility data were correlated well by using the modified Apelblat equation, the λh equation and the van’t Hoff equation, respectively. The Akaike’s Information Criterion (AIC) was used to select the best model for correlating the solubility of cefuroxime acid. Furthermore, the dissolution enthalpy, entropy and Gibbs free energy change of cefuroxime acid were also calculated by using the van’t Hoff equation

  10. Self-consistent field model for strong electrostatic correlations and inhomogeneous dielectric media

    Electrostatic correlations and variable permittivity of electrolytes are essential for exploring many chemical and physical properties of interfaces in aqueous solutions. We propose a continuum electrostatic model for the treatment of these effects in the framework of the self-consistent field theory. The model incorporates a space- or field-dependent dielectric permittivity and an excluded ion-size effect for the correlation energy. This results in a self-energy modified Poisson-Nernst-Planck or Poisson-Boltzmann equation together with state equations for the self energy and the dielectric function. We show that the ionic size is of significant importance in predicting a finite self energy for an ion in an inhomogeneous medium. Asymptotic approximation is proposed for the solution of a generalized Debye-Hückel equation, which has been shown to capture the ionic correlation and dielectric self energy. Through simulating ionic distribution surrounding a macroion, the modified self-consistent field model is shown to agree with particle-based Monte Carlo simulations. Numerical results for symmetric and asymmetric electrolytes demonstrate that the model is able to predict the charge inversion at high correlation regime in the presence of multivalent interfacial ions which is beyond the mean-field theory and also show strong effect to double layer structure due to the space- or field-dependent dielectric permittivity

  11. Mean propagation kernels for transport in correlated stochastic media at unresolved scales, illustration with a problem in atmospheric radiation

    A simple and effective framework is presented for modeling transport processes unfolding at computationally and/or observationally unresolved scales in scattering, absorbing and emitting media. The new approach acts directly on the spatial (i.e., propagation) part of the kernel in the integral formulation of the generic linear transport equation framed for stochastic media with a wide variety of spatial correlations, going far beyond the Markov-Poisson class used in the classic Pomraning-Levermore model. This statistical look at the extinction of un-collided particle beams takes us away from the standard exponential law of transmission. New transmission laws arise that are generally not exponential, often not even for asymptotically large jumps. This means that, from this perspective on random spatial variability, there is no 'effective medium' per se nor homogenization technique that can be used to describe the effects of unresolved fluctuations of the collision coefficient. However, one can still rewrite the transport equation, at least in its integral form, in a manner that looks like its counterpart for uniform media, but with a modified propagation kernel. Implementation in a Monte Carlo scheme is trivially simple and numerical results are presented that illustrate the bulk effect of the new parameterization for plane-parallel geometry. We survey time-domain diagnostics of solar radiative transfer in the Earth's cloudy atmosphere obtained recently from high-resolution ground-based spectroscopy, and it is shown that they are explained comprehensively by the new model. Finally, we discuss possible applications of this modeling framework in nuclear engineering. (authors)

  12. Effect of media compositions on α-glucosidase inhibitory activity, growth and fatty acid content in mycelium extracts of Colletotrichum sp. TSC13 from Taxus Sumatrana (Miq.) de Laub.

    Artanti, Nina; Tachibana, Sanro; Kardono, Leonardus B S

    2014-07-01

    The active α-glucosidase inhibitor compounds in the endophytic fungus Colletotrichum sp. TSC13 were found to be the unsaturated fatty acids (oleic, linoleic and linolenic acids). These compounds have potential as antidiabetic agents. The aim of the present study is to investigate the effects of various media composition on growth (mycelium dry weight) and the fatty acids content (μg mg(-1) mycelium DW) of Colletotrichum sp. TSC13 in relation to its α-glucosidase inhibitory activity. For that purpose, the experiments were set up by varying the carbon and nitrogen sources, metal ions and desaturase and fatty acid synthase inhibitors in the media. Colletotrichum sp. TSC13 grown on potato dextrose broth (PDB) was used as control. The α-glucosidase inhibitory activities were (range from 43.9 ± 2.5 to 88.6 ± 5.2%) at 10 μg mL(-1). This activity seemed to correlate with the unsaturated fatty acids content of the samples. Different sugars as carbon source experiment showed that xylose gave the highest growth (938.7 ± 141.6 mg). However, the highest fatty acids content was obtained from fructose medium which containing linoleic acid (38.8 ± 4.9 μ g mg(-1) DW). Soluble starch gave better growth (672.5 ± 62.3 mg) but very low fatty acids content (2.8 ± 0.1 μg mg(-1) DW) was obtained. Yeast extract was the best nitrogen source. Fatty acids production was better as compared to beef extract and soytone. This is the first report of various media compositions on fatty acids content in Colletotrichum sp. TSC13 in relation to its α-glucosidase inhibitory activity. PMID:26035936

  13. Correlation between lipid profile & carotid intima media thickness in cerebral ischemia.

    Sengupta, Debalina; Bardhan, Jayati; Baran, Anil; Mahapatra, Singha; Banerjee, Joyshree; Rout, Jayanta Kumar

    2014-01-01

    Cerebrovascular accident or stroke is defined by an abrupt onset of neurological deficit that is attributable to a focal vascular cause. Stroke is a major cause of morbidity and mortality worldwide. This may result from brain infarction or hemorrhage. Carotid atherosclerosis is a reasonable risk factor for cerebral ischemic stroke. Deranged lipid metabolism due to various modifiable and non-modifiable risk factors leads to the pathogenesis of atherosclerosis. This study is intended to find out any association between altered lipid metabolism (Cholesterol, Triglycerides, LDL : HDL ratio) and development of cerebral ischemia. An observational case control study was conducted with 50 cases of cerebral ischemia and 50 age & sex matched healthy controls within age group 50-70 years. After inclusion of cases and controls and taking informed consent they underwent history taking, proper clinical examination & biochemical investigations (lipid profile). Then data were collected and results were statistically analyzed using Chi-square test & Independent Sample "T-test". The study showed altered lipid profile is associated with cerebral ischemia by increasing carotid intima media thickness (IMT). There was significant (p cerebral ischemic stroke thereby reducing morbidity and mortality. PMID:26215001

  14. Study of Correlation Between Glucose Concentration and Reduced Scattering Coefficients in Turbid media using Optical Coherence Tomography

    Poddar, R; Sen, P; Andrews, J T

    2008-01-01

    Noninvasive, non-contact and \\textit{in vivo} monitoring of blood glucose is a long needed pathology tool for saving patients from recurring pain and hassle that can accompany conventional blood glucose testing methods. Optical coherence tomography known for its high axial resolution imaging modality is adopted in this article for monitoring glucose levels in tissue like media non-invasively. Making use of changes in reduced scattering coefficient due to the refractive-index mismatch between the extracellular fluid and the cellular membranes and armed with a theoretical model, we establish a correlation between the glucose concentration and reduced scattering coefficient. The scattering coefficients are extracted from the deconvoluted interference signal by using Monte-Carlo simulation with valid approximations. A program code using NI LabVIEW(^{TM}) is developed for automation of the experiment, data acquisition and analysis.

  15. Extraction of trace thorium from hydrochloric acid media by 1-phenyl-3-methyl-4-benzoyl-5-pyrazolone

    YANG Wei-Fan; YUAN Shuang-Gui; XU Yan-Bing; XIAO Yong-Hou; XIONG Bing

    2003-01-01

    The paper describes the solvent extraction of trace thorium from hydrochloric acid media by1-phenyl-3-methyl-4-benzoyl-5-pyrazolone (PMBP) using a radioactive tracer technique. The percent extraction ofthorium was studied as a function of acidity, PMBP concentration and equilibrium time. The back-extraction behaviorof thorium from the organic phase was also tested. Separation of thorium was performed from fission products pro-duced in 14 MeV neutron bombardment of natural uranium by employing the PMBP extraction procedure. Thegamma-ray spectra of the separated thorium fractions show that thorium can be separated from most of fission prod-ucts and a large amount of uranium.

  16. Extraction and separation of U(VI) and Th(IV) from hydrobromic acid media using Cyanex-923 extractant

    Ghag Snehal M.; Pawar Suresh D.

    2010-01-01

    A systematic study of the solvent extraction of uranium(VI) and thorium(IV) from hydrobromic acid media was performed using the neutral phosphine oxide extractant Cyanex-923 in toluene. These metal ions were found to be quantitatively extracted with Cyanex-923 in toluene in the acidity range 5x10-5-1x10-4 M and 5x10-5-5x10-3 M, respectively, and they are stripped from the organic phase with 7.0 M HClO4 and 2.0- 4.0 M HCl, respectively. The effect of the equilibrium period, diluents, div...

  17. Dissolution Profile of Mefenamic Acid Solid Dosage Forms in Two Compendial and Biorelevant (FaSSIF) Media.

    Nurhikmah, Wilda; Sumirtapura, Yeyet Cahyati; Pamudji, Jessie Sofia

    2016-01-01

    Mefenamic acid is a non-steroidal anti-inflammatory drug (NSAID) that is widely used for the treatment of mild-to-moderate pain. Mefenamic acid belongs to the Biopharmaceutical Classification System (BCS) class II drug which has lower water solubility but high permeability. There are two different compendial methods available for dissolution tests of mefenamic acid solid dosage forms, i.e. methods of United States Pharmacopeia 37 (USP) and Pharmacopoeia of the People's Republic of China 2010 (PPRC). Indonesian Pharmacopeia V ed. (FI) adopted the USP method. On the other hand, many researches focused on the use of a 'biorelevant' medium to develop the dissolution test method. The aim of this research was to study the dissolution profile of mefenamic acid from its solid dosage forms (caplet and capsule) available in the Indonesian market with three different dissolution medium: USP, PPRC, and biorelevant fasted simulated small intestinal fluid (FaSSIF) media. The tested products consisted of the innovator's product (available only in caplet dosage form, FN caplet) and generic products (available as caplet and capsule). The dissolution test of the drug products in all dissolution media was performed in 900 mL of medium using apparatus II (paddle) at a temperature of 37°C and rotation speed of 75 rpm, except for the capsule product and for USP medium, both of which tests were done using apparatus I (basket) with rotation speed of 100 rpm. The solubility test of mefenamic acid was carried out in all media at temperature of 37°C. The result obtained from the solubility test showed that the the highest solubility of mefenamic acid was obtained in USP medium (approximately 2 mg/mL), followed by PPRC medium (about 0.5 mg/mL), and FaSSIF medium (approximately 0.06 mg/ml). In the dissolution test, percentage of drug dissolved in in the USP and PPRC media after 45 min for all products reached more than 75%, except for the PN caplet in USP medium which reached only about 44

  18. Analysis of embryo, cytoplasmic and maternal genetic correlations for seven essential amino acids in rapeseed meal (Brassica napus L.)

    Guo Lin Chen; Jian Guo Wu; Murali-Tottekkaad Variath; Zhong Wei Yang; Chun Hai Shi

    2011-04-01

    Genetic correlations of nutrient quality traits including lysine, methionine, leucine, isoleucine, phenylalanine, valine and threonine contents in rapeseed meal were analysed by the genetic model for quantitative traits of diploid plants using a diallel design with nine parents of Brassica napus L. These results indicated that the genetic correlations of embryo, cytoplasm and/or maternal plant havemade different contribution to total genetic correlations of most pairwise nutrient quality traits. The genetic correlations among the amino acids in rapeseed meal were simultaneously controlled by genetic main correlations and genotype × environment (GE) interaction correlations, especially for the maternal dominance correlations. Most components of genetic main correlations and GE interaction correlations for the pairwise traits studied were significantly positive. Some of the pairwise traits had negative genetic correlations, especially between valine and other amino acid contents. Indirect selection for improving the quality traits of rapeseed meal could be expected in rape breeding according to the magnitude and direction of genetic correlation components.

  19. Pd-catalyzed ethylene methoxycarbonylation with Brønsted acid ionic liquids as promoter and phase-separable reaction media

    Garcia-Suarez, Eduardo J.; Khokarale, Santosh Govind; Nguyen van Buu, Olivier;

    2014-01-01

    Brønsted acid ionic liquids (BAILs) were prepared and applied as combined acid promoters and reaction media in Pd–phosphine catalyzed methoxycarbonylation of ethylene to produce methyl propionate. The BAILs served as alternatives to common mineral acids required for the reaction, e.g. methanesulf...

  20. Serum Uric Acid Correlation with Echocardiographic Indices in Children with Dilated Cardiomyopathy

    Shahrokh Rajaei

    2009-12-01

    Full Text Available Background: Dilated cardiomyopathy (DCMP is a myocardial disease characterized by dilated left ventricle or both ventricles and reduced contractility of the myocardium. In patients suffering from DCMP, the serum level of uric acid may increase. This research was designed to evaluate the effect of the serum level of uric acid on systolic and diastolic functions in patients with DCMP.Methods: This case-control study was performed on 30 patients with DCMP aged between 1 month and 12 years who were consistent with a control group in terms of age and gender. Patients suffering from congenital and acquired cardiac, renal, metabolic, endocrine, musculoskeletal, neurologic, vascular, and hematologic diseases were excluded. After physical examination, chest X-ray, and electrocardiography, systolic and diastolic parameters were measured via echocardiography, and fasting serum uric acid level was measured. The data were analyzed using the t-test and Pearson correlation coefficient.Results: The average age of the patients in the case and control groups was 7.28 and 7.13 years, respectively. There were 15 boys, and the rest were girls. The serum uric acid level in the case and control groups was 6.22 and 3.31 mg/dl, respectively; the difference was statistically significant (P value <0.01. There was a significant correlation between serum uric acid level and left ventricular isovolumic contraction, interventricular septal diameter, left ventricular septal diameter in diastole, and fractional shortening (P value <0.05.Conclusion: In children with DCMP, the serum level of uric acid increases significantly and this increase is significantly correlated with some of left heart echocardiographic parameters. This test is of predictive value for disease progression.

  1. Facilitated transport of titanium dioxide nanoparticles by humic substances in saturated porous media under acidic conditions

    Zhang, Ruichang [Chinese Academy of Sciences, Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science (China); Zhang, Haibo; Tu, Chen; Hu, Xuefeng; Li, Lianzhen [Chinese Academy of Sciences, Key Laboratory of Coastal Environmental Processes and Ecological Remediation, Yantai Institute of Coastal Zone Research (China); Luo, Yongming, E-mail: ymluo@yic.ac.cn; Christie, Peter [Chinese Academy of Sciences, Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science (China)

    2015-04-15

    The transport behavior of titanium dioxide nanoparticles (TiO{sub 2} NPs, 30 nm in diameter) was studied in well-defined porous media composed of clean quartz sand over a range of solution chemistry under acidic conditions. Transport of TiO{sub 2} NPs was dramatically enhanced by humic substances (HS) at acidic pH (4.0, 5.0 and 6.0), even at a low HS concentration of 0.5 mg L{sup −1}. Facilitated transport of TiO{sub 2} NPs was likely attributable to the increased stability of TiO{sub 2} NPs and repulsive interaction between TiO{sub 2} NPs and quartz sands due to the adsorbed HS. The mobility of TiO{sub 2} NPs was also increased with increasing pH from 4.0 to 6.0. Although transport of TiO{sub 2} NPs was insensitive to low ionic strength, it was significantly inhibited by high concentrations of NaCl and CaCl{sub 2}. In addition, calculated Derjaguin–Landau–Verwey–Overbeek (DLVO) interaction energy indicated that high energy barriers were responsible for the high mobility of TiO{sub 2} NPs, while the secondary energy minimum could play an important role in the retention of TiO{sub 2} NPs at 100 mmol L{sup −1} NaCl. Straining and gravitational settlement of larger TiO{sub 2} NPs aggregates at 1 mg L{sup −1} HS, pH 5.0, and 2 mmol L{sup −1} CaCl{sub 2} could be responsible for the significant retention even in the presence of high energy barriers. Moreover, more favorable interaction between approaching TiO{sub 2} NPs and TiO{sub 2} NPs that had been already deposited on the collector resulted in a ripening-shape breakthrough curve at 2 mmol L{sup −1} CaCl{sub 2}. Overall, a combination of mechanisms including DLVO-type force, straining, and physical filtration was involved in the retention of TiO{sub 2} NPs over the range of solution chemistry examined in this study.

  2. Facilitated transport of titanium dioxide nanoparticles by humic substances in saturated porous media under acidic conditions

    The transport behavior of titanium dioxide nanoparticles (TiO2 NPs, 30 nm in diameter) was studied in well-defined porous media composed of clean quartz sand over a range of solution chemistry under acidic conditions. Transport of TiO2 NPs was dramatically enhanced by humic substances (HS) at acidic pH (4.0, 5.0 and 6.0), even at a low HS concentration of 0.5 mg L−1. Facilitated transport of TiO2 NPs was likely attributable to the increased stability of TiO2 NPs and repulsive interaction between TiO2 NPs and quartz sands due to the adsorbed HS. The mobility of TiO2 NPs was also increased with increasing pH from 4.0 to 6.0. Although transport of TiO2 NPs was insensitive to low ionic strength, it was significantly inhibited by high concentrations of NaCl and CaCl2. In addition, calculated Derjaguin–Landau–Verwey–Overbeek (DLVO) interaction energy indicated that high energy barriers were responsible for the high mobility of TiO2 NPs, while the secondary energy minimum could play an important role in the retention of TiO2 NPs at 100 mmol L−1 NaCl. Straining and gravitational settlement of larger TiO2 NPs aggregates at 1 mg L−1 HS, pH 5.0, and 2 mmol L−1 CaCl2 could be responsible for the significant retention even in the presence of high energy barriers. Moreover, more favorable interaction between approaching TiO2 NPs and TiO2 NPs that had been already deposited on the collector resulted in a ripening-shape breakthrough curve at 2 mmol L−1 CaCl2. Overall, a combination of mechanisms including DLVO-type force, straining, and physical filtration was involved in the retention of TiO2 NPs over the range of solution chemistry examined in this study

  3. Discrete volumetric digital image correlation for the investigation of granular type media at microscale: accuracy assessment

    Bornert M.

    2010-06-01

    Full Text Available The recent development of efficient 3D imaging tools such as X-Rays computed microtomography combined with the extension to volumetric images of Digital Image Correlation (DIC techniques provide new insights on the analysis of materials and structures. Among many other possible fields of application, geomaterials are good candidates for such investigations, owing to their relative transparency to X-rays and the presence in many samples of a natural contrast suitable for deformation mapping. However, these materials often deform discontinuously at microscale, for instance in the form of the development of a networks of microcracks. Discontinuity is even the dominant rule in granular-type materials such as sand in which the contribution to overall deformation of the microcontinuous phenomena -elastic strains inside grains- are negligible. To investigate deformation at the scale of these discontinuous mechanisms, specific DIC algorithms are required, which override the assumption of continuity of the transformation at the scale of the correlation windows. The recent so-called Discrete-DIC procedure (Hall et al, 2010 is a possible answer. We recall here its general principles and focus on its potential accuracy, from both theoretical and practical points of view. We show that the position and the rotation of individual grains with an average diameter of 500µm can be determined from images recorded with a laboratory microCT scanner, with a 15µm voxel size, with an accuracy of the order of 1µm and 0,1 degree, respectively.

  4. Uric acid correlates to oxidation and inflammation in opposite directions in women

    Wu, Sheng Hui; Shu, Xiao Ou; Milne, Ginger; Xiang, Yong-Bing; Zhang, Xianglan; Cai, Qiuyin; Fazio, Sergio; Linton, MacRae F; Chen, Honglei; Purdue, Mark; Rothman, Nathaniel; Gao, Yu-Tang; Zheng, Wei; Yang, Gong

    2016-01-01

    Objective To evaluate the association of uric acid (UA) levels with a panel of markers of oxidative stress and inflammation. Methods Plasma UA levels, along with a panel of oxidative stress and inflammatory markers, were measured in 755 Chinese women. Results Plasma UA levels were inversely associated with urinary levels of the oxidative stress marker F2-isoprostanes and positively correlated to levels of inflammatory markers such as C-reactive protein and some proinflammatory cytokines (tumor necrosis factor-α and interleukin-6) in blood as well as prostaglandin E2 metabolites in urine. Conclusions Plasma UA levels correlate to oxidation and inflammation biomarkers in opposite directions in women. PMID:26301880

  5. Correlation between leptin level with lipid profile and free fatty acid in liver cirrhosis patients

    Siti Maryani; Neneng Ratnasari; Siti Nurdjanah

    2015-01-01

    Malnutrition is a common condition in liver cirrhotic patients. Leptin regulates body weightphysiologically by suppressing appetite and increasing energy expenditure. Leptin is higher in femalethan male. Studies have shown correlation between leptin with metabolic factors like body massindex (BMI) and lipid profile in cirrhotic patients. This study was conducted to investigate thecorrelation between serum leptin levels with lipid profile and free fatty acid in male patients with livercirrhosi...

  6. Correlations of folic acid, vitamin B12, homocysteine, and thrombopoietin to platelet count in HCV infection

    Somayh S. Eissa; Olfat M. Hendy; Fatma Younis; Aziza K. Omar Samy; Ayat R. Abdallah; Laila A. Ahmed

    2012-01-01

    IntroductionThe platelet count is known to decrease in proportion to the advancement of the stage of liver disease in chronic hepatitis C (CHC) viral infection. The platelet count is currently used as an index for fibrosis staging. The pathophysiology of thrombocytopenia (TCP) in patients with hepatitis C virus (HCV) infection is not completely understood. PurposeThis work aimed to study the correlations of folic acid (FA), vitamin B12 (Vit B12), homocysteine (Hcy), and thrombopoietin to t...

  7. Kinetic and Mechanistic Studies of Oxidation of an Antiallergic Drug with Bromamine-T in Acid and Alkaline Media

    Cetrizine dihydrochloride (CTZH) is widely used as an anti-allergic drug. Sodium N-bromo-p-toluenesulfonamide or bromamine-T (BAT) is the bromine analogue of chloramine-T (CAT) and is found to be a better oxidizing agent than CAT. In the present research, the kinetics of oxidation of CTZH with BAT in acid and alkaline media was studied at 313 K. The experimental rate laws obtained are: -d[BAT]/dt = k[BAT] [CTZH]0.80[H+]-0.48 in acid medium and -d[BAT]/dt = k[BAT][CTZH]0.48[OH-]0.52[PTS]-0.40 in alkaline medium where PTS is p-toluenesulfonamide. Activation parameters and reaction constants were evaluated. The solvent isotope effect was studied using D2O. The dielectric effect is positive. The stoichiometry of the reaction was found to be 1:1 and the oxidation products were identified as 4-chlorobenzophenone and (2-piperazin-1-yl-ethoxy)-acetic acid in both media. The rate of oxidation of CTZH is faster in acid medium. Suitable mechanisms and related rate laws have been worked out

  8. An efficient protocol for incorporation of an unnatural amino acid in perdeuterated recombinant proteins using glucose-based media

    Venditti, Vincenzo; Fawzi, Nicolas L.; Clore, G. Marius, E-mail: mariusc@mail.nih.gov [National Institutes of Health, Laboratory of Chemical Physics, National Institute of Diabetes and Digestive and Kidney Diseases (United States)

    2012-03-15

    The in vivo incorporation of unnatural amino acids into proteins is a well-established technique requiring an orthogonal tRNA/aminoacyl-tRNA synthetase pair specific for the unnatural amino acid that is incorporated at a position encoded by a TAG amber codon. Although this technology provides unique opportunities to engineer protein structures, poor protein yields are usually obtained in deuterated media, hampering its application in the protein NMR field. Here, we describe a novel protocol for incorporating unnatural amino acids into fully deuterated proteins using glucose-based media (which are relevant to the production, for example, of amino acid-specific methyl-labeled proteins used in the study of large molecular weight systems). The method consists of pre-induction of the pEVOL plasmid encoding the tRNA/aminoacyl-tRNA synthetase pair in a rich, H{sub 2}O-based medium prior to exchanging the culture into a D{sub 2}O-based medium. Our protocol results in high level of isotopic incorporation ({approx}95%) and retains the high expression level of the target protein observed in Luria-Bertani medium.

  9. Correlation between mastitis occurrence and the count of microorganisms in bulk raw milk of bovine dairy herds in four selective culture media.

    Souto, Luís I M; Minagawa, Clarice Y; Telles, Evelise O; Garbuglio, Márcio A; Amaku, Marcos; Melville, Priscilla A; Dias, Ricardo A; Sakata, Sonia T; Benites, Nilson R

    2010-02-01

    Milk is the normal secretion of the mammary gland, practically free of colostrum and obtained by the complete milking of one or more healthy animals. Mastitis is an inflammatory process of the mammary gland and it may cause alterations in the milk. The present work aimed to verify whether it is possible, by means of the counts of microorganism in the bulk raw milk in four selective culture media, to establish a correlation with the occurrence of mastitis and therefore, to monitor this disease in bovine dairy herds. The following selective culture media were used: KF Streptococcus Agar, Edwards Agar, Baird-Parker Agar, Blood Agar plus potassium tellurite. Spearman's correlation coefficient was calculated in order to compare the occurrence of mastitis (percentage) in each herd with respective selective culture media counts of microorganisms in bulk raw milk. Thirty-six possibilities were analysed (Tamis and CMT-positive rates were compared with the log-transformed count in four selective culture media) and there was a negative correlation between Tamis 3 and the Baird-Parker Agar plate count. The total results of microbiological tests showed that there were three correlations of the counts in selective culture media. Fifty-two possibilities were analysed and there was a negative correlation between no-bacterial-growth mastitis rates and log10 of KF Streptoccocus Agar plate count and there were two positive correlations between coagulase-positive staphylococci and log10 of Baird-Parker Agar plate count and Blood Agar plus potassium tellurite plate count. PMID:19939321

  10. Fundamental Mechanistic Understanding of Electrocatalysis of Oxygen Reduction on Pt and Non-Pt Surfaces: Acid versus Alkaline Media

    Nagappan Ramaswamy

    2012-01-01

    Full Text Available Complex electrochemical reactions such as Oxygen Reduction Reaction (ORR involving multi-electron transfer is an electrocatalytic inner-sphere electron transfer process that exhibit strong dependence on the nature of the electrode surface. This criterion (along with required stability in acidic electrolytes has largely limited ORR catalysts to the platinum-based surfaces. New evidence in alkaline media, discussed here, throws light on the involvement of surface-independent outer-sphere electron transfer component in the overall electrocatalytic process. This surface non-specificity gives rise to the possibility of using a wide-range of non-noble metal surfaces as electrode materials for ORR in alkaline media. However, this outer-sphere process predominantly leads only to peroxide intermediate as the final product. The importance of promoting the electrocatalytic inner-sphere electron transfer by facilitation of direct adsorption of molecular oxygen on the active site is emphasized by using pyrolyzed metal porphyrins as electrocatalysts. A comparison of ORR reaction mechanisms between acidic and alkaline conditions is elucidated here. The primary advantage of performing ORR in alkaline media is found to be the enhanced activation of the peroxide intermediate on the active site that enables the complete four-electron transfer. ORR reaction schemes involving both outer- and inner-sphere electron transfer mechanisms are proposed.

  11. The Lewis acid catalyzed synthesis of hyperbranched Oligo(glycerol-diacid)s in aprotic polar media

    The Lewis-acid, titanium (IV) butoxide (15% (w/w; catalyst/reactants)), was used to catalyze the condensation of 0.05 mol glycerol with 0.10 mol of either succinic acid, glutaric acid, or azelaic acid to produce oligomers. The reactions were refluxed in dilute solutions of dimethylsulfoxide (DMSO) o...

  12. Correlation of Internet use for health care engagement purposes and HIV clinical outcomes among HIV-positive individuals using online social media

    Saberi, Parya; Johnson, Mallory O.

    2015-01-01

    Our objective was to describe mobile telephone and Internet use and assess the correlation of Internet use for health care engagement (HCE) purposes and HIV clinical outcomes among HIV-positive individuals. We conducted a national survey using online social media to examine mobile telephone and Internet use, self-reported HIV viral load (VL; detectable versus undetectable), and antiretroviral adherence rating (excellent versus

  13. Decontamination of media filters in a groundwater treatment plant by dissolution processes using organic acid solutions

    Ground water was collected from a depth of 1,200 m in the Al-Qasim area in mid-Saudi Arabia. This underground water contains minerals, mainly Fe and Mn and radio-nuclides like radium and other ionic materials. This water was filtered through a sand bed, which contains layers of sands of different sizes in order to remove those impurities from water. Mn and Fe were deposited on outer layer of each sand granule during filtration and radium was adsorbed on surfaces of these minerals. Ra was separated from these minerals by dissolving them in various acids such as ascorbic acid, citric acid, tannic acid, salicylic acid, tartaric acid and lactic acid under different experimental conditions like acid concentration, contact time, shaking speed, particle size, temperature and liquid/solid ratio. The effectiveness of these acids on radium removal was found as follows: ascorbic acid ∼ citric acid > tartaric acid > tannic acid > lactic acid > salicylic acid. Various reaction parameters were also optimized. Reaction kinetic and mechanism parameters of dissolution process were studied and compared with other published data. (author)

  14. Effect of Mixed Acid Media on the Positive Side of the Hybrid Zinc-Cerium Redox Flow Battery

    Highlights: • Small concentrations of hydrochloric acid (0.5 - 1 mol L−1) in 0.6 mol L−1 Cerium and 4 mol L−1 MSA favored the Ce3+/4+ reaction making it significantly faster and more reversible. • The D values of the mixed acid media were larger than those of containing only MSA, especially for the oxidation reaction and increased with increasing temperatures. • The EIS results showed that the solution resistance of the mixed electrolytes is considerably lower than unmixed electrolyte. • The stability of the solutions containing 0.6 mol L−1 was found dependent on temperature and state of charge. Higher temperatures (>40 °C) and state of charge (>60% Ce4+) lead to precipitation. - Abstract: The electrochemical activity of the Ce3+/4+reaction in the presence of various mixed acid electrolytes containing methanesulfonic acid (MSA) as the base electrolyte along with hydrochloric, nitric and sulfuric acid was investigated as a function of acid concentration and reaction temperature on a Pt disk electrode. Cyclic voltammetry in 0.6 mol L−1 cerium and 4 mol L−1 MSA with 0.5 - 1 mol L−1hydrochloric acid showed that the reversibility and kinetics of the Ce3+/4+reaction were significantly enhanced compared to that containing MSA only. Higher diffusion coefficients (D) and exchange current densities (jo) were also obtained for the mixed acid media containing sulfuric and nitric acid, but in this case the reversibility of the reaction was not that improved. Higher concentrations of hydrochloric, nitric and sulfuric acid (>1 mol L−1) made the oxidation of Ce3+ very hard to delineate from the cyclic voltammograms because of the side reactions occurring at such high potentials. The exchange current density (jo), obtained through polarization resistance and electrochemical impedance spectroscopy measurements (EIS), increased with temperature over the range 25 to 55 °C. The EIS results showed that the solution resistance of the mixed electrolytes is

  15. Correlation between microstructural characteristics and weight loss of natural stones exposed to simulated acid rain.

    Franzoni, Elisa; Sassoni, Enrico

    2011-12-15

    The correlation between stone microstructural characteristics and material degradation (in terms of weight loss), in given environmental conditions, was investigated. Seven lithotypes, having very different microstructural characteristics, were used. Four acidic aqueous solutions were prepared to simulate acid rain (two adding H(2)SO(4) and two adding HNO(3) to deionized water, in order to reach, for each acid, pH values of 5.0 and 4.0), and deionized water at pH=5.6 was used to simulate clean rain. Stone samples were then immersed in such aqueous solutions, the surface alteration being periodically inspected and the weight loss periodically measured. After 14 days of immersion, a good correlation was found between weight loss and the product of carbonate content and specific surface area in the starting materials. This was explained considering that this product accounts for the weight loss owing to the sample's fraction actually composed of calcite (the most soluble fraction) and the effective surface area exposed to dissolving solution (which depends on stone porosity and pore size distribution). Such correlation between stone microstructure and degradation may be useful for comparing the durability of different lithotypes, in given environmental conditions, and quantitatively predicting the weight loss of a lithotype, compared to another one. Hence, the correlation found in this study may be used to specifically tailor to various stone types, with different microstructural characteristics, some results that have been calculated in literature for specific stone types and then proposed as possibly representative for a broad category of stones with similar characteristics. PMID:22030245

  16. Improvement of production of citric acid from oil palm empty fruit bunches: optimization of media by statistical experimental designs.

    Bari, Md Niamul; Alam, Md Zahangir; Muyibi, Suleyman A; Jamal, Parveen; Abdullah-Al-Mamun

    2009-06-01

    A sequential optimization based on statistical design and one-factor-at-a-time (OFAT) method was employed to optimize the media constituents for the improvement of citric acid production from oil palm empty fruit bunches (EFB) through solid state bioconversion using Aspergillus niger IBO-103MNB. The results obtained from the Plackett-Burman design indicated that the co-substrate (sucrose), stimulator (methanol) and minerals (Zn, Cu, Mn and Mg) were found to be the major factors for further optimization. Based on the OFAT method, the selected medium constituents and inoculum concentration were optimized by the central composite design (CCD) under the response surface methodology (RSM). The statistical analysis showed that the optimum media containing 6.4% (w/w) of sucrose, 9% (v/w) of minerals and 15.5% (v/w) of inoculum gave the maximum production of citric acid (337.94 g/kg of dry EFB). The analysis showed that sucrose (p<0.0011) and mineral solution (p<0.0061) were more significant compared to inoculum concentration (p<0.0127) for the citric acid production. PMID:19231166

  17. F2-isoprostanes are correlated with trans fatty acids in the plasma of pregnant women

    Larose, Jessica; Julien, Pierre; Greffard, Karine; Fraser, William D.; Audibert, Francois; Wei, Shu Qin; Bilodeau, Jean-François

    2016-01-01

    We hypothesized that the mild physiological oxidative stress present during pregnancy could increase both, plasma F2-isoprostanes (F2-isoPs) by lipid oxidation and trans fatty acids (TFA) through cis-trans isomerization respectively. Plasma samples collected at 12–18 weeks (MIROS cohort; n=65) and 38–41 weeks of pregnancy (CHUL cohort; n = 21) were subjected to alkaline hydrolysis followed by liquid-liquid extraction in order to extract total F2-isoPs for quantification by HPLC-MS/MS. Several positive correlations were found between F2-isoPs and TFA, measured by GC-FID in plasma phospholipids, such as 6t-18:1, 9t-18:1 and 9t,12c-18:2 (r > 0.306; p < 0.045). Despite its low level, the 9t,12c-18:2 trans isomer, known to be associated to cardiovascular diseases, showed the most significant correlations with F2-isoPs. No correlation was observed between F2-isoPs and 9t-16:1 or 11t-18:1. In summary, this study suggests either a concomitant phenomenon or a competition between lipid peroxidation and cis-trans isomerisation of the cis precursor fatty acid in vivo during pregnancy. PMID:25312493

  18. Inflence of S and Mn on ICC susceptibility of 02Kh18N13 steel in nitric acid media

    The paper studies the impact of S and Mn additions on grain boundary stability of annealed and tempered samples of 02Kh18N13 steel in nitric acid media with additions and without ions of hexavalent chromium. A negative impact of the medium and manganese is established for annealed samples which were tempered at 600 deg C for more than 50 h. This effect is presimably related to grain boundary segreagation of sulphur and manganese and accelerating impact of these elements on chromium deplition of the boundaries of sensitized steel grains

  19. Baphia nitida Leaves Extract as a Green Corrosion Inhibitor for the Corrosion of Mild Steel in Acidic Media

    Njoku, V. O.; E. E. Oguzie; Obi, C.; Ayuk, A. A.

    2014-01-01

    The inhibiting effect of Baphia nitida (BN) leaves extract on the corrosion of mild steel in 1 M H2SO4 and 2 M HCl was studied at different temperatures using gasometric and weight loss techniques. The results showed that the leaves extract is a good inhibitor for mild steel corrosion in both acid media and better performances were obtained in 2 M HCl solutions. Inhibition efficiency was found to increase with increasing inhibitor concentration and decreasing temperature. The addition of hali...

  20. Social Media Usage In European Clubs Football Industry. Is Digital Reach Better Correlated With Sports Or Financial Performane?

    Teodor Dima

    2015-01-01

    Social media is likely the marketing and communication channel which grew fastest from "unique and modern" to "mandatory". Presented as a solution for the future, usage of media channels has already become a key part of any brand promoting campaign or business expansion effort. And football clubs line up with this trend. Development of the new media elements solves two fundamental needs for business units specialized in sports: the need for faster and more efficient communication with fans - ...

  1. Nitric acid adduct formation during crystallization of barium and strontium nitrates and their co-precipitation from nitric acid media

    The molar solubilities of Ba, Sr and Pb nitrates in nitric acid as a function of total nitrate concentration is presented and described by the mass action law, indicating on formation of the adducts with nitric acid. Precipitates of Ba(NO3)2 and Sr(NO3)2 crystallized from nitric acid were studied by ISP OES and IR spectroscopy. The data obtained confirmed formation of metastable adducts with nitric acid. IR and X-ray diffraction studies of the mixed salt systems indicated conversion of the mixed salts into (Ba,Sr)(NO3)2 solid solution of discrete structure in range of total nitrate ion concentration ∼6 mol/L. (author)

  2. Corrosion Inhibition of Mild Steel by Various Plant Extracts in Acid Media

    Osita Obiukwu; Ignatius Opara; Lawan U. Grema

    2015-01-01

    The aim of this study is to investigate the corrosion inhibition of some plant extracts on mild steel in selected media. The plant extracts investigated are Okazi leaf (Gnetum africanum), Utazi leaf (Gongronema latifolium) and Elizabeth leaf (Chromolena odaratum). The selected media are 1M HCL and H2SO4 and the corrosion rate on the mild steel was investigated using mass loss method. Results were obtained at intervals of 24, 48, 72 and 96 h, respectively. The corrosion rate and inhibition eff...

  3. Correlated Strontium and Barium Isotopic Compositions of Acid-Cleaned Single Silicon Carbides from Murchison

    Liu, Nan; Gallino, Roberto; Davis, Andrew M; Bisterzo, Sara; Gyngard, Frank; Kaeppeler, Franz; Cristallo, Sergio; Dauphas, Nicolas; Pellin, Michael J; Dillmann, Iris

    2015-01-01

    We present strontium, barium, carbon, and silicon isotopic compositions of 61 acid-cleaned presolar SiC grains from Murchison. Comparison with previous data shows that acid washing is highly effective in removing both strontium and barium contamination. For the first time, by using correlated $^{88}Sr$/$^{86}Sr$ and $^{138}Ba$/$^{136}Ba$ ratios in mainstream SiC grains, we are able to resolve the effect of $^{13}C$ concentration from that of $^{13}C$-pocket mass on s-process nucleosynthesis, which points towards the existence of large $^{13}C$-pockets with low $^{13}C$ concentration in AGB stars. The presence of such large $^{13}$R-pockets with a variety of relatively low $^{13}C$ concentrations seems to require multiple mixing processes in parent AGB stars of mainstream SiC grains.

  4. Correlation between leptin level with lipid profile and free fatty acid in liver cirrhosis patients

    Siti Maryani

    2015-09-01

    Full Text Available Malnutrition is a common condition in liver cirrhotic patients. Leptin regulates body weightphysiologically by suppressing appetite and increasing energy expenditure. Leptin is higher in femalethan male. Studies have shown correlation between leptin with metabolic factors like body massindex (BMI and lipid profile in cirrhotic patients. This study was conducted to investigate thecorrelation between serum leptin levels with lipid profile and free fatty acid in male patients with livercirrhosis. This was a cross sectional study that conducted at Gastroentero-Hepatology Clinic andInternal Ward at Dr. Sardjito General Hospital, Yogyakarta. The inclusion criteria were patients withliver cirrhosis > 18 years old, male, with Child-Pugh classification B and C, and provided informedconsent. The exclusion criteria were liver cirrhotic patients with comorbidity chronic kidney disease,chronic heart failure, diabetic, cancer, infection/septic, pregnancy, breast feeding, and steroid use.Data collecting was performed by anamnesis, physical examination, abdominal ultrasonographyexamination, and blood chemistry test. Pearson test was used to evaluate the correlation betweenthe serum leptin level with the lipid profile and free fatty acid. The results showed that no significantnegative correlation was observed between the serum leptin level with the total cholesterol (r= -0.052; p=0.766, high-density lipoprotein/HDL (r= -0.078; p=0.658 and triglyceride (r= -0.170; p=0.328 in male patients with liver cirrhosis. Furthermore, no significant positive correlationwas observed between the serum leptin levels with the low-density lipoprotein/LDL (r= -0.013; p=0.942 and free fatty acid/FFA (r= 0.007; p=0.968. In conclusion, there was no correlationbetween serum leptin levels with lipid profile and FFA in male patients with liver cirrhosis.

  5. Trend analysis of the correlation of amino acid plasma profile with glycemic status in Saudi diabetic patients

    Fahad A. Al-Abbasi

    2012-10-01

    Full Text Available The role of amino acids in diabetes mellitus and its metabolic traits have been suggested previously; however, studied to a very limited scale in the Saudi patient population. Patients diagnosed with diabetes mellitus were included in the current clinical study. Sample was representative and in accordance with the national population distribution. Blood samples were drawn and assayed for glucose, total cholesterol, triglyceride, high density lipoprotein and low density lipoprotein. General biochemical markers, such as alkaline phosphatase (ALP, creatinine kinase (CK, aspartate transaminase (AST, alanine transaminase (ALT and blood urea nitrogen (BUN were assessed. Serum amino acids of different categories (essential, semi-essential and metabolic indicator amino acids were assessed. Correlation co-efficient between each amino acid and serum glucose level was calculated. The current study showed positive correlation between amino acid level and glucose serum concentration in male while it showed negative correlation in female Saudi diabetic patients. Male patients had significantly higher methionine concentration parallel to their glycemic status. Metabolic indicator amino acids significantly changed in concordance with the glycemic status of female patients more than in male patients. In conclusion, serum amino acid is positively correlated with glycemic status in Saudi male diabetic patients while negatively correlated in female patients. Yet, further study would be recommended to utilize serum amino acid profile as surrogate parameter for the metabolic complications of diabetes mellitus.

  6. Selective liquid-liquid extraction of antimony(III from hydrochloric acid media by N-n-octylaniline in xylene

    M. A. ANUSE

    2004-04-01

    Full Text Available N-n-Octylaniline in xylene was used for the extraction separation of antimony(III from hydrochloric acid media. Antimony(III was extracted quantitatively with 10 mL 4 % N-n-octylaniline in xylene. It was stripped from the organic phase with 0.5 M ammonia and estimated photometrically by the iodide method. The effect of metal ion, acid, reagent concentration and various foreign ions was investigated. The method affords binary and ternary separation of antimony(III from tellurium(IV, selenium(IV, lead(II, bismuth(III, tin(IV, germanium(IV, copper(II, gold(III, iron(III and zinc(II. The method is applicable for the analysis of synthetic mixtures, alloys and semiconductor thin films. It is fast, accurate and precise.

  7. Copper- or manganese-doped ZnS quantum dots as fluorescent probes for detecting folic acid in aqueous media

    3-Mercaptopropionic acid-capped core/shell ZnS:Cu/ZnS and ZnS:Mn/ZnS doped quantum dots (QDs) prepared through hydrothermal methods exhibit high photoluminescence intensity as well as good photostability. These water-dispersible nanoparticles exhibit high fluorescence sensitivity to folic acid due to the high affinity of the carboxylate groups and nitrogen atoms of folic acid towards the Zn surface atoms of the doped dots. Quenching of the fluorescence intensity of the QDs allows the detection of folic acid concentrations as low as 11 μM, thus affording a very sensitive system for the sensing of this biologically active molecule in aqueous solution. The possible quenching mechanism is discussed. - Graphical abstract: A sensitive method for the detection of folic acid based on the fluorescence quenching of Mn- or Cu-doped ZnS quantum dots was developed. Highlights: ► Quenching of the fluorescence intensity of doped ZnS QDs in the presence of folic acid. ► New fluorescent sensors for folic acid. ► Detection of folic acid concentrations as low as 11 μM in aqueous solution. ► The Perrin model and fluorescence lifetimes of ZnS:Mn QDs demonstrate a static quenching mechanism. ► Quenching efficiency of ZnS:Cu QDs correlates with the Stern-Volmer model.

  8. Correlation between the production of exopolysaccharides and oxalic acid secretion by Ganoderma applanatum and Tyromyces palustris.

    Osińska-Jaroszuk, Monika; Wlizło, Kamila; Szałapata, Katarzyna; Jarosz-Wilkołazka, Anna

    2014-12-01

    The secretion of exopolysaccharides and oxalic acid in cultures of a white rot Ganoderma applanatum strain and a brown rot Tyromyces palustris strain were tested in terms of culture time, pH range, and temperature. The high yield of exopolysaccharides (EPS) required a moderate temperature of 28 °C for G. applanatum and 20 °C for T. palustris. G. applanatum and T. palustris accumulated more EPS when the concentration of the carbon source (maltose for G. applanatum and fructose for T. palustris) was 30 g/L. The results indicate that the production of oxalic acid by G. applanatum is correlated with the initial pH value of the culture medium and the concentration of oxalic acid increased to 1.66 ± 0.2 mM at the initial pH of 6.5 during the fungal growth. During the growth of T. palustris, the reduction of the initial pH value of the growing medium lowered the oxalic acid concentration from 7.7 ± 0.6 mM at pH 6.0 to 1.99 ± 0.2 mM at pH 3.5. T. palustris accumulated considerably more oxalic acid than G. applanatum and its presence did not affect significantly the production of exopolysaccharides. We also observed that the maximum amounts of exopolysaccharides secreted during cultivation of G. applanatum and T. palustris were 45.8 ± 1.2 and 19.1 ± 1.2 g/L, respectively. PMID:25178492

  9. Inhibition of corrosion of mild steel in acid media by N′-benzylidene-3-(quinolin-4-ylthio)propanohydrazide

    V Ramesh Saliyan; Airody Vasudeva Adhikari

    2008-08-01

    In the present investigation a new corrosion inhibitor, N′-(3,4-dihydroxybenzylidene)-3-{[8-(trifluoromethyl) quinolin-4-yl]thio}propanohydrazide(DHBTPH) was synthesized, characterized and tested as a corrosion inhibitor for mild steel in HCl (1 M, 2 M) and H2SO4 (0.5 M, 1 M) solutions using weight-loss method, electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization methods. The corrosion inhibition efficiency measured by all the above three techniques were in good agreement with each other. The results showed that DHBTPH is a very good inhibitor for mild steel in acidic media. The inhibition efficiency in different acid media was found to be in the decreasing order 0.5 M H2SO4 > 1 M HCl > 1 M H2SO4 > 2 M HCl. The inhibition efficiency increases with increasing inhibitor concentration and with increasing temperature. It acts as an anodic inhibitor. Thermodynamic and activation parameters are discussed. Adsorption of DHBTPH was found to follow the Langmuir’s adsorption isotherm. Chemisorption mechanism is proposed. The mild steel samples were also analysed by scanning electron microscopy (SEM).

  10. Synthesis of ascorbyl oleate by transesterification of olive oil with ascorbic acid in polar organic media catalyzed by immobilized lipases.

    Moreno-Perez, Sonia; Filice, Marco; Guisan, Jose M; Fernandez-Lorente, Gloria

    2013-09-01

    The reaction of transesterification between oils (e.g., olive oil) and ascorbic acid in polar anhydrous media (e.g., tert-amyl alcohol) catalyzed by immobilized lipases for the preparation of natural liposoluble antioxidants (e.g., ascorbyl oleate) was studied. Three commercial lipases were tested: Candida antarctica B lipase (CALB), Thermomyces lanuginosus lipase (TLL) and Rhizomucor miehei lipase (RML). Each lipase was immobilized by three different protocols: hydrophobic adsorption, anionic exchange and multipoint covalent attachment. The highest synthetic yields were obtained with CALB adsorbed on hydrophobic supports (e.g., the commercial derivative Novozym 435). The rates and yields of the synthesis of ascorbyl oleate were higher when using the solvent dried with molecular sieves, at high temperatures (e.g. 45°C) and with a small excess of oil (2 mol of oil per mol of ascorbic acid). The coating of CALB derivatives with polyethyleneimine (PEI) improved its catalytic behavior and allowed the achievement of yields of up to 80% of ascorbyl oleate in less than 24h. CALB adsorbed on a hydrophobic support and coated with PEI was 2-fold more stable than a non-coated derivative and one hundred-fold more stable than the best TLL derivative. The best CALB derivative exhibited a half-life of 3 days at 75°C in fully anhydrous media, and this derivative maintained full activity after 28 days at 45°C in dried tert-amyl alcohol. PMID:23891831

  11. 14C octanoic acid breath tests correlate with scintigraphy in the critically ill

    Full text: Gastric stasis is common in the critically ill and reduces tolerance to nasogastric feeding. Scintigraphic measurement of gastric emptying is rarely used in the critically ill for practical reasons. Breath testing would be a more convenient way of determining gastric emptying. The purpose of this study was to validate 14C octanoic acid breath tests against scintigraphy in ventilated patients. 21 unselected mechanically ventilated patients receiving enteral nutrition via a nasogastric tube (14M, mean age 58yrs) were fed a dual radiolabelled nutrient meal consisting of 100ml Ensure, 74KBq 14C octanoic acid and 20MBq 99Tc sulphur colloid. 12 normal volunteers (9M mean age 38yrs) were also studied to establish normal ranges. Dynamic scintigraphic images were collected with subjects in 20 deg LAO position over 4 hours utilising a GE Starcam 300M mobile gamma camera. Breath samples were collected using the RAH 'Rapid-14' collection methodology at baseline and every 10 -15 minutes for 4 hours. Gastric emptying parameters were calculated and correlated. Normal breath test mean t- = 117min (SD=46). Delayed gastric emptying was seen in some of the critically ill patients, mean t- - 143 mm (SD=86). Strongest correlations were between normals scintigraphic t- (t-s) and breath test t- (t-B), r=0.96 (p-B, r=0.75 (p-s and t-B, n=16, r=0.73 (p14C octanoic acid breath tests in normal subjects and the critically ill. This may be a useful alternative for measurement of gastric emptying in the critically ill. Copyright (2002) The Australian and New Zealand Society of Nuclear Medicine Inc

  12. MUSIC in triple-resonance experiments: amino acid type-selective (1)H-(15)N correlations

    Schubert; Smalla; Schmieder; Oschkinat

    1999-11-01

    Amino acid type-selective triple-resonance experiments can be of great help for the assignment of protein spectra, since they help to remove ambiguities in either manual or automated assignment procedures. Here, modified triple-resonance experiments that yield amino acid type-selective (1)H-(15)N correlations are presented. They are based on novel coherence transfer schemes, the MUSIC pulse sequence elements, that replace the initial INEPT transfer and are selective for XH(2) or XH(3) (X can be (15)N or (13)C). The desired amino acid type is thereby selected based on the topology of the side chain. Experiments for Gly (G-HSQC); Ala (A-HSQC); Thr, Val, Ile, and Ala (TAVI-HSQC); Thr and Ala (TA-HSQC), as well as Asn and Gln (N-HSQC and QN-HSQC), are described. The new experiments are recorded as two-dimensional experiments and therefore need only small amounts of spectrometer time. The performance of the experiments is demonstrated with the application to two protein domains. Copyright 1999 Academic Press. PMID:10527741

  13. MUSIC in Triple-Resonance Experiments: Amino Acid Type-Selective 1H- 15N Correlations

    Schubert, Mario; Smalla, Maika; Schmieder, Peter; Oschkinat, Hartmut

    1999-11-01

    Amino acid type-selective triple-resonance experiments can be of great help for the assignment of protein spectra, since they help to remove ambiguities in either manual or automated assignment procedures. Here, modified triple-resonance experiments that yield amino acid type-selective 1H-15N correlations are presented. They are based on novel coherence transfer schemes, the MUSIC pulse sequence elements, that replace the initial INEPT transfer and are selective for XH2 or XH3 (X can be 15N or 13C). The desired amino acid type is thereby selected based on the topology of the side chain. Experiments for Gly (G-HSQC); Ala (A-HSQC); Thr, Val, Ile, and Ala (TAVI-HSQC); Thr and Ala (TA-HSQC), as well as Asn and Gln (N-HSQC and QN-HSQC), are described. The new experiments are recorded as two-dimensional experiments and therefore need only small amounts of spectrometer time. The performance of the experiments is demonstrated with the application to two protein domains.

  14. Corrosion Study of Stainless Steels in Peracetic Acid Bleach Media With and Without Chloride and Chelant

    Rohtash; Ajay K Singh; Rajendra Kumar

    2014-01-01

    The paper industries are adopting non-chlorine containing chemicals e.g. peroxide, ozone, peracids etc. as alternate of chlorine based bleach chemicals e.g. chlorine and chlorine dioxide etc. with the aim of eco-friend atmospheres. Changeover to the new chemicals in the bleaching process is likely to affect the metallurgy of the existing bleach plants due to change in the corrosivity of the media. Accordingly, corrosion investigations were performed in a peracid namely peracetic a...

  15. Monitoring Lactic Acid Fermentation in Media Containing Dandelion (Taraxacum officinale) by FTIR Spectroscopy

    Dan C. Vodnar; Pop, Oana L; Socaciu, Carmen

    2012-01-01

    Fourier-transform infrared (FTIR) spectroscopy is considered to be a comprehensive and sensitive method for detection of molecular changes in cells and media. In the present study, FTIR spectroscopy was employed as an easy, rapid and reliable technique to evaluate the lactic fermentation of Lactobacillus casei on a model de Man, Rogosa and Sharpe (MRS) medium with or without the addition of dandelion extract (DE). Dandelion, due to its high content in fructans, can be used as an additional ca...

  16. Separation and immobilization of Sr and Cs contained in acidic media by using inorganic ion-exchangers. Literature survey

    The present study deals with the survey of inorganic ion-exchangers suitable for separation and immobilization of Sr and Cs contained in acidic high-level liquid waste. The stabilities of published waste forms and their preparation processes were evaluated from the standpoint of conversion of exchangers containing Sr and Cs into appropriate waste forms. The essential results are below. (1) For separation and immobilization of Cs, crystalline silicotitanate seems to be the most promising exchanger. Insoluble ferrocyanides and phosphates are not suitable for immobilization without additives. Mordenite is inexpensive and commercially available but it would dissolve in highly acidic media. (2) For selective separation of Sr, there is no promising exchanger up to now. It is necessary either to modify separation condition or to synthesize a novel exchanger. (3) Soluble salts, glasses and ceramics are proposed as a storage or disposal form of separated Sr and Cs. Ceramics sintered by hot-pressing are favorable waste forms of inorganic ion-exchangers but their leachabilities and thermal conductivities are largely influenced by qualities of products. Crystallinity of a sintered exchanger depends on its composition. Exchanges of low Cs contents are often converted into amorphous materials whose chemical stabilities depend on solubilities of components of exchangers. (4) A new exchanger to be synthesized is crystalline and selective toward Sr and Cs. One meq/g is enough for Sr and Cs capacities, which are restricted by thermal and transmutation effects. Composition of the exchanger should be selected from the point of a scenario of separation and disposal. The solubilities of SiO2, TiO2, ZrO2, Nb2O5 and Ta2O5 are low in acidic media and those of Al2O3, TiO2 and ZrO2, in disposal circumstances. (5) Future works are optimization of separation scheme including development of exchangers, simplification of solidification step and cost-benefit analysis. (author)

  17. Uranium, Cesium, and Mercury Leaching and Recovery from Cemented Radioactive Wastes in Sulfuric Acid and Iodide Media

    Nicolas Reynier

    2015-11-01

    Full Text Available The Canadian Nuclear Laboratories (CNL is developing a long-term management strategy for its existing inventory of solid radioactive cemented wastes, which contain uranium, mercury, fission products, and a number of minor elements. The composition of the cemented radioactive waste poses significant impediments to the extraction and recovery of uranium using conventional technology. The goal of this research was to develop an innovative method for uranium, mercury and cesium recovery from surrogate radioactive cemented waste (SRCW. Leaching using sulfuric acid and saline media significantly improves the solubilization of the key elements from the SRCW. Increasing the NaCl concentration from 0.5 to 4 M increases the mercury solubilization from 82% to 96%. The sodium chloride forms a soluble mercury complex when mercury is present as HgO or metallic mercury but not with HgS that is found in 60 °C cured SRCW. Several leaching experiments were done using a sulfuric acid solution with KI to leach SRCW cured at 60 °C and/or aged for 30 months. Solubilization yields are above 97% for Cs and 98% for U and Hg. Leaching using sulfuric acid and KI improves the solubilization of Hg by oxidation of Hg0, as well as HgS, and form a mercury tetraiodide complex. Hg and Cs were selectively removed from the leachate prior to uranium recovery. It was found that U recovery from sulfuric leachate in iodide media using the resin Lewatit TP260 is very efficient. Considering these results, a process including effluent recirculation was applied. Improvements of solubilization due to the recycling of chemical reagents were observed during effluent recirculation.

  18. A time-dependent, two-step binding mode of the nitro dye flavianic acid to trypsin in acid media

    Schneedorf J.M.

    2001-01-01

    Full Text Available Synthetic dyes bind to proteins causing selective coprecipitation of the complexes in acid aqueous solution by a process of reversible denaturation that can be used as an alternative method for protein fractionation. The events that occur before precipitation were investigated by equilibrium dialysis using bovine trypsin and flavianic acid as a model able to cause coprecipitation. A two-step mode of interaction was found to be dependent on the incubation periods allowed for binding, with pronounced binding occurring after 42 h of incubation. The first step seems to involve hydration effects and conformational changes induced by binding of the first dye molecule, following rapid denaturation due to the binding of six additional flavianate anions to the macromolecule.

  19. Formation of complex precursors of amino acids by irradiation of simulated interstellar media with heavy ions

    Kobayashi, K.; Suzuki, N.; Taniuchi, T.; Kaneko, T.; Yoshida, S.

    A wide variety of organic compounds have been detected in such extraterrestrial bodies as meteorites and comets Amino acids were identified in the extracts from Murchison meteorite and other carbonaceous chondrites It is hypothesized that these compounds are originally formed in ice mantles of interstellar dusts ISDs in molecular clouds by cosmic rays and ultraviolet light UV Formation of amino acid precursors by high energy protons or UV irradiation of simulated ISDs was reported by several groups The amino acid precursors were however not well-characterized We irradiated a frozen mixture of methanol ammonia and water with heavy ions to study possible organic compounds abiotically formed in molecular clouds by cosmic rays A mixture of methanol ammonia and water was irradiated with carbon beams 290 MeV u from a heavy ion accelerator HIMAC of National Institute of Radiological Sciences Japan Irradiation was performed either at room temperature liquid phase or at 77 K solid phase The products were characterized by gel filtration chromatography GFC FT-IR pyrolysis PY -GC MS etc Amino acids were analyzed by HPLC and GC MS after acid hydrolysis or the products Amino acids such as glycine and alanine were identified in the products in both the cases of liquid phase and solid phase irradiation Energy yields G-values of glycine were 0 014 liquid phase and 0 007 solid phase respectively Average molecular weights of the products were estimated as to 2300 in both the case Aromatic hydrocarbons N-containing heterocyclic

  20. Free fatty acid has a negative correlation with myocardial uptake of FDG

    Free fatty acid (FFA) is a marker of insulin resistance. Myocardial uptake of FDG is influenced by insulin resistance. We investigated the correlation of FFA and myocardial uptake of FDG in whole body PET. We measured serum FFA levels in consecutive 112 patients who underwent whole body FDG PET due to malignancy work up. Twelve patients with diabetes. 13 with liver disease, 4 with suspicious ischemic heart disease. 1 with steroid therapy, and 10 with final diagnosis of benign disease were excluded. After fasting of diet or beverages for at least 6 hours, blood was aspirated at peripheral vein for measurement of FFA and glucose in serum. FDG was injected as a dose of 0.14 mCi/kg body weight. Fifty minutes later, whole body PET scan was performed from skull base to upper thigh. Maximum SUV (maxSUV) using lean body weight was obtained in heart. liver, cerebellum, muscle and malignant tissues. Finally 72 patients (M:F 45:27, age 56.9±15.8 years) were enrolled. There were 27 non small cell lung cancer, 14 lymphoma, 10 esophageal cancer, 3 breast cancer, 3 colon cancer, 3 renal cell cancer, 2 melanoma, and 10 other cancers. Serum glucose level was 96.6±14.3 mg/dL. Serum FFA level was 720.0±315.2 uEq/L. MaxSUV of main malignant tissue ranged from 0.7 to 11.5 (mean 4.9±2.6). MaxSUV of each organs were 1.0 to 14.6 (mean 4.0±3.0) in heart, 2.7 to 6.4 (mean 3.9±0.6) in cerebellum, 1.0 to 2.6 (mean 1.9±0.3) in liver, and 0.6 to 1.1 (mean 0.8±0.1) in gluteal muscle. FFA and maxSUV of heart had a negative correlation. The best fitting line was MaxSUV of Heart = -4.4583 x In(FF A) + 32.964. But FFA had no correlation with any other parameters like serum glucose level, and MaxSUV of cerebellum, muscle, liver and malignant tissues. We found a negative correlation between FFA levels and myocardial uptake of FDG. FFA modifying drugs such as nicotinic acid derivatives may have influence on myocardial uptake of FDG

  1. Anomalous aryl strengthening of americium and europium complexes during extraction by alkylenediphosphine dioxides from perchloric acid media

    Extraction of americium and europium from perchlorate environments by solutions of three types of methylenediphosphine dioxides, namely (C6H5)P(O)(CH2)sub(n)(O)P(C6H5)2, (C6H5)2P(O)CH2(O)P(C8H17)2 and (C8H17)2P(O)(CH2)sub(n)(O)P(C8H17)2 has been studied (n is 1 or 2 ) The diluents used have been dichlorethane and chloroform. In perchlorate environments the distribuiton coefficients of americium and europium have proved to be by about 3 orders of magnitude higher than in nitric acid environments, i.e. in perchlorate media the complexes are far more stable. Separation coefficients of americium and REE in perchloric acid soutions are much higher than in nitrate environments. The average value of Am/Eu separation coeffecient at 1-5 M acidity was about 6 (with dichlorethane as diluent) or about 7 (with chloroform as diluent). The complexes essentially exist as trisolvated. Americium complexes display anomalous stability increase upon being diluted: by about 2 orders of magnitude with dichlorethane and by up to 3 orders of magnitude with chloroform used as diluent

  2. Simulated Raman correlation spectroscopy for quantifying nucleic acid-silver composites

    Freeman, Lindsay M.; Smolyaninov, Alexei; Pang, Lin; Fainman, Yeshaiahu

    2016-03-01

    Plasmonic devices are of great interest due to their ability to confine light to the nanoscale level and dramatically increase the intensity of the electromagnetic field, functioning as high performance platforms for Raman signal enhancement. While Raman spectroscopy has been proposed as a tool to identify the preferential binding sites and adsorption configurations of molecules to nanoparticles, the results have been limited by the assumption that a single binding site is responsible for molecular adsorption. Here, we develop the simulated Raman correlation spectroscopy (SRCS) process to determine which binding sites of a molecule preferentially bind to a plasmonic material and in what capacity. We apply the method to the case of nucleic acids binding to silver, discovering that multiple atoms are responsible for adsorption kinetics. This method can be applied to future systems, such as to study the molecular orientation of adsorbates to films or protein conformation upon adsorption.

  3. Simulated Raman correlation spectroscopy for quantifying nucleic acid-silver composites

    Freeman, Lindsay M.; Smolyaninov, Alexei; Pang, Lin; Fainman, Yeshaiahu

    2016-01-01

    Plasmonic devices are of great interest due to their ability to confine light to the nanoscale level and dramatically increase the intensity of the electromagnetic field, functioning as high performance platforms for Raman signal enhancement. While Raman spectroscopy has been proposed as a tool to identify the preferential binding sites and adsorption configurations of molecules to nanoparticles, the results have been limited by the assumption that a single binding site is responsible for molecular adsorption. Here, we develop the simulated Raman correlation spectroscopy (SRCS) process to determine which binding sites of a molecule preferentially bind to a plasmonic material and in what capacity. We apply the method to the case of nucleic acids binding to silver, discovering that multiple atoms are responsible for adsorption kinetics. This method can be applied to future systems, such as to study the molecular orientation of adsorbates to films or protein conformation upon adsorption. PMID:27010074

  4. Experimental Study and Numerical Solution of Poly Acrylic Acid Supported Magnetite Nanoparticles Transport in a One-Dimensional Porous Media

    M. Golzar

    2014-01-01

    Full Text Available Recently, iron nanoparticles have attracted more attention for groundwater remediation due to its potential to reduce subsurface contaminants such as PCBs, chlorinated solvents, and heavy metals. The magnetic properties of iron nanoparticles cause to attach to each other and form bigger colloid particles of iron nanoparticles with more rapid sedimentation rate in aqueous environment. Using the surfactants such as poly acrylic acid (PAA prevents iron nanoparticles from forming large flocs that may cause sedimentation and so increases transport distance of the nanoparticles. In this study, the transport of iron oxide nanoparticles (Fe3O4 stabilized with PAA in a one-dimensional porous media (column was investigated. The slurries with concentrations of 20,100 and 500 (mg/L were injected into the bottom of the column under hydraulic gradients of 0.125, 0.375, and 0.625. The results obtained from experiments were compared with the results obtained from numerical solution of advection-dispersion equation based on the classical colloid filtration theory (CFT. The experimental and simulated breakthrough curves showed that CFT is able to predict the transport and fate of iron oxide nanoparticles stabilized with PAA (up to concentration 500 ppm in a porous media.

  5. Low Serum Lysosomal Acid Lipase Activity Correlates with Advanced Liver Disease

    Eyal Shteyer

    2016-02-01

    Full Text Available Fatty liver has become the most common liver disorder and is recognized as a major health burden in the Western world. The causes for disease progression are not fully elucidated but lysosomal impairment is suggested. Here we evaluate a possible role for lysosomal acid lipase (LAL activity in liver disease. To study LAL levels in patients with microvesicular, idiopathic cirrhosis and nonalcoholic fatty liver disease (NAFLD. Medical records of patients with microvesicular steatosis, cryptogenic cirrhosis and NAFLD, diagnosed on the basis of liver biopsies, were included in the study. Measured serum LAL activity was correlated to clinical, laboratory, imaging and pathological data. No patient exhibited LAL activity compatible with genetic LAL deficiency. However, serum LAL activity inversely predicted liver disease severity. A LAL level of 0.5 was the most sensitive for detecting both histologic and noninvasive markers for disease severity, including lower white blood cell count and calcium, and elevated γ-glutamyltransferase, creatinine, glucose, glycated hemoglobin, uric acid and coagulation function. Serum LAL activity <0.5 indicates severe liver injury in patients with fatty liver and cirrhosis. Further studies should define the direct role of LAL in liver disease severity and consider the possibility of replacement therapy.

  6. Low Serum Lysosomal Acid Lipase Activity Correlates with Advanced Liver Disease.

    Shteyer, Eyal; Villenchik, Rivka; Mahamid, Mahmud; Nator, Nidaa; Safadi, Rifaat

    2016-01-01

    Fatty liver has become the most common liver disorder and is recognized as a major health burden in the Western world. The causes for disease progression are not fully elucidated but lysosomal impairment is suggested. Here we evaluate a possible role for lysosomal acid lipase (LAL) activity in liver disease. To study LAL levels in patients with microvesicular, idiopathic cirrhosis and nonalcoholic fatty liver disease (NAFLD). Medical records of patients with microvesicular steatosis, cryptogenic cirrhosis and NAFLD, diagnosed on the basis of liver biopsies, were included in the study. Measured serum LAL activity was correlated to clinical, laboratory, imaging and pathological data. No patient exhibited LAL activity compatible with genetic LAL deficiency. However, serum LAL activity inversely predicted liver disease severity. A LAL level of 0.5 was the most sensitive for detecting both histologic and noninvasive markers for disease severity, including lower white blood cell count and calcium, and elevated γ-glutamyltransferase, creatinine, glucose, glycated hemoglobin, uric acid and coagulation function. Serum LAL activity liver injury in patients with fatty liver and cirrhosis. Further studies should define the direct role of LAL in liver disease severity and consider the possibility of replacement therapy. PMID:26927097

  7. Baphia nitida Leaves Extract as a Green Corrosion Inhibitor for the Corrosion of Mild Steel in Acidic Media

    V. O. Njoku

    2014-01-01

    Full Text Available The inhibiting effect of Baphia nitida (BN leaves extract on the corrosion of mild steel in 1 M H2SO4 and 2 M HCl was studied at different temperatures using gasometric and weight loss techniques. The results showed that the leaves extract is a good inhibitor for mild steel corrosion in both acid media and better performances were obtained in 2 M HCl solutions. Inhibition efficiency was found to increase with increasing inhibitor concentration and decreasing temperature. The addition of halides to the extract enhanced the inhibition efficiency due to synergistic effect which improved adsorption of cationic species present in the extract and was in the order KCl < KBr < KI suggesting possible role of radii of the halide ions. Thermodynamic parameters determined showed that the adsorption of BN on the metal surface is an exothermic and spontaneous process and that the adsorption was via a physisorption mechanism.

  8. The corrosion behaviour of WC-VC-Co hardmetals in acidic media

    The effect of increasing vanadium carbide (VC) content on the corrosion behaviour of tungsten carbide - 10 wt% cobalt hardmetals was investigated in 1 M hydrochloric (HCl), and sulphuric (H2SO4) acids solutions. Increasing VC content makes the open circuit potential (OCP) in the test solutions more negative than the base alloy. Specimens exhibited pseudo passivation in all the test solutions. Increasing VC led to decreasing corrosion current density. However, the corrosion current densities during chronoamperometric tests were lower for 0 wt% VC. XRD and Raman spectroscopy showed that hydrated WO3 formed in the surface films of all specimens in hydrochloric acid (HCl), while hydrated vanadyl sulphate also formed for higher VC content specimens in sulphuric acid (H2SO4).

  9. Interactions of short chain phenylalkanoic acids within ionic surfactant micelles in aqueous media

    Naeem Kashif

    2012-01-01

    Full Text Available % SDS KR nema Solubilization and interactions of phenylalkanoic acids induced by cationic surfactant, cetyltrimethylammonium bromide (CTAB and an anionic surfactant, sodium dodecyl sulfate (SDS was investigated spectrophotometrically at 25.0°C. The UV spectra of the additives (acids were measured with and without surfactant above and below critical micelle concentration (cmc of the surfactant. The presence of alkyl chain in phenylalkanoic acids is responsible for hydrophobic interaction resulting in shift of the spectra towards longer wavelength (red shift. The value of partition coefficient (Kx between the bulk water and surfactant micelles and in turn standard free energy change of solubilization (ΔGpº were also estimated by measuring the differential absorbance (ΔA of the additives in micellar solutions.

  10. The corrosion behaviour of WC-VC-Co hardmetals in acidic media

    Konadu, D.S.; Merwe, J. van der [DST/NRF Centre of Excellence in Strong Materials, School of Chemical and Metallurgical Engineering, University of the Witwatersrand, P.O. Private Bag 3, WITS 2050 (South Africa); Potgieter, J.H. [School of Biology, Chemistry and Health Sciences, Division of Chemistry and Materials, Manchester Metropolitan University, Oxford Road, Manchester M 1 5GD (United Kingdom); Potgieter-Vermaak, S. [School of Chemistry, University of the Witwatersrand, P.O. Private Bag 3, WITS 2050 (South Africa); Machio, C.N., E-mail: cmachio@csir.co.z [Council for Scientific and Industrial Research (CSIR), Materials Science and Manufacturing, P.O. Box 395, PRETORIA 0001 (South Africa)

    2010-09-15

    The effect of increasing vanadium carbide (VC) content on the corrosion behaviour of tungsten carbide - 10 wt% cobalt hardmetals was investigated in 1 M hydrochloric (HCl), and sulphuric (H{sub 2}SO{sub 4}) acids solutions. Increasing VC content makes the open circuit potential (OCP) in the test solutions more negative than the base alloy. Specimens exhibited pseudo passivation in all the test solutions. Increasing VC led to decreasing corrosion current density. However, the corrosion current densities during chronoamperometric tests were lower for 0 wt% VC. XRD and Raman spectroscopy showed that hydrated WO{sub 3} formed in the surface films of all specimens in hydrochloric acid (HCl), while hydrated vanadyl sulphate also formed for higher VC content specimens in sulphuric acid (H{sub 2}SO{sub 4}).

  11. Theoretical study of inhibition efficiencies of some amino acids on corrosion of carbon steel in acidic media: green corrosion inhibitors.

    Dehdab, Maryam; Shahraki, Mehdi; Habibi-Khorassani, Sayyed Mostafa

    2016-01-01

    Inhibition efficiencies of three amino acids [tryptophan (B), tyrosine (c), and serine (A)] have been studied as green corrosion inhibitors on corrosion of carbon steel using density functional theory (DFT) method in gas and aqueous phases. Quantum chemical parameters such as EH OMO (highest occupied molecular orbital energy), E LUMO (lowest unoccupied molecular orbital energy), hardness (η), polarizability ([Formula: see text]), total negative charges on atoms (TNC), molecular volume (MV) and total energy (TE) have been calculated at the B3LYP level of theory with 6-311++G** basis set. Consistent with experimental data, theoretical results showed that the order of inhibition efficiency is tryptophan (B) > tyrosine (C) > serine (A). In order to determine the possible sites of nucleophilic and electrophilic attacks, local reactivity has been evaluated through Fukui indices. PMID:26347374

  12. Levels of polyunsaturated fatty acids correlate with growth rate in plant cell cultures

    Meï, Coline; Michaud, Morgane; Cussac, Mathilde; Albrieux, Catherine; Gros, Valérie; Maréchal, Eric; Block, Maryse A.; Jouhet, Juliette; Rébeillé, Fabrice

    2015-01-01

    In higher plants, fatty acids (FAs) with 18 carbons (18C) represent about 70% of total FAs, the most abundant species being 18:2 and 18:3. These two polyunsaturated FAs (PUFAs) represent about 55% of total FAs in Arabidopsis cell suspension cultures, whereas 18:1 represents about 10%. The level of PUFAs may vary, depending on ill-defined factors. Here, we compared various sets of plant cell cultures and noticed a correlation between the growth rate of a cell population and the level of unsaturation of 18C FAs. These observations suggest that the final level of PUFAs might depend in part on the rate of cell division, and that FAD2 and FAD3 desaturases, which are respectively responsible for the formation of 18:2 and 18:3 on phospholipids, have limiting activities in fast-growing cultures. In plant cell culture, phosphate (Pi) deprivation is known to impair cell division and to trigger lipid remodeling. We observed that Pi starvation had no effect on the expression of FAD genes, and that the level of PUFAs in this situation was also correlated with the growth rate. Thus, the level of PUFAs appears as a hallmark in determining cell maturity and aging. PMID:26469123

  13. Extraction of nitric acid from aqueous media with OφD(iB)CMPO-n-dodecane

    A study of the extraction characteristics of nitric acid with octyl(phenyl)-N,N-diisobutylcarbamoylmethyl phosphine oxide [OφD(iB)CMPO or, simply, CMPO] was conducted. In the experimental program, CMPO was dissolved in n-dodecane to produce the organic extracting medium. The objectives of the project were to infer extraction stoichiometry and to estimate equilibrium constants for the extraction of nitric acid with the CMPO extractant. Experiments were performed over a limited range of concentrations to avoid conditions favoring formation of a third phase. Aqueous nitric acid concentrations were limited to 0.30 M at 25 C, 1.0 M at 40 C, and 3.0 M at 50 C. The data indicate that CMPO extracts nitric acid with a 1:1 stoichiometry. The value of the equilibrium constant is estimated at 2.66 ± 0.09 at 25 C. The enthalpy of the extraction is estimated to be -5.46 ± 0.46 kcal/mol

  14. Kinetics and Mechanism of Oxidation of Methimazole by Chlorite in Slightly Acidic Media.

    Chipiso, Kudzanai; Simoyi, Reuben H

    2016-06-01

    The kinetics and mechanism of the oxidation of methimazole (1-methyl-3H-imidazole), MMI, by chlorite in mildly acidic environments were studied. It is a complex reaction that gives oligo-oscillations in chlorine dioxide concentrations in excess chlorite conditions. The stoichiometry is strictly 2:1, with the sulfur center being oxidized to sulfate and the organic moiety being hydrolyzed to several indeterminate species. In excess MMI conditions over chlorite, the sulfinic acid and sulfonic acid were observed as major intermediates. The sulfenic acid, which was observed in the electrochemical oxidation of MMI, was not observed with chlorite oxidations. Initial reduction of chlorite produced HOCl, an autocatalytic species in chlorite oxidations. HOCl rapidly reacts with chlorite to produce chlorine dioxide, which, in turn, reacts rapidly with MMI to produce more chlorite. The reaction of chlorine dioxide with MMI is competitive, in rate, with the chlorite-MMI and HOCl-ClO2(-) reactions. This explains the oligo-oscillations in ClO2 concentrations. PMID:27126471

  15. Polymerization of euphorbia oil with Lewis acid in carbon dioxide media

    Boron trifluoride diethyl etherate (BF3-OEt2) Lewis acid catalyzed ring-opening polymerization of euphorbia oil (EO), a natural epoxy oil, in liquid carbon dioxide was conducted in an effort to develop useful vegetable oil based polymers. The resulting polymers (RPEO) were characterized by FTIR, 1H-...

  16. Spectrophotometric determination of beryllium with sulfochlorophenol S in organo-aqueous acetic-acid media

    The possibility has been shown of photometric determination of beryllium with sulphochlorophenol S using an acetic acid-propanol mixture (1:1), containing 0.5-1.5 vol% of water, as the reaction medium. Under such conditions, the reaction between beryllium and sulphochlorophenol S is sensitive and selective with respect to some easily hydrolized elements (Sn, Bi, Sb, Hg) as well as to Ga, In, Tl, Zn in the presence of HCl. The following excess amounts do not interfere with the determination of 0.45 μg Be: Hg-1.2x104, Sb-6.2x103, In-2.5x103, Tl-2.0x103, Zn-1.4x103, Ga-1.2x103. The reaction between beryllium and sulphochlorophenol S is selective with respect to a number of complexing agents. Beryllium can be determined in the presence of 150000-200000 times its weight amounts of tartaric, citric and boric acids, 5000-sulphosalycilic acid, 6000-oxalic acid, 6000-dimethyl glyoxime, 150-8-hydroxyquinoline

  17. Inhibition of the Corrosion of Mild Steel in Acid Media by Naturally Occurring Acacia Senegal

    Urvija Garg; Tak, R. K.

    2010-01-01

    The inhibition of corrosion of mild steel in HCl solution by naturally occurring Acacia Senegal has been studied in relation to the concentration of inhibitor and concentration of corrosive medium. It has been observed that the Acacia Senegal alcoholic extract acts as a good corrosion inhibitor in hydrochloric acid solution and the adsorption of the extract provides a good protection against mild steel corrosion.

  18. Determination of the optimum conditions for boric acid extraction with carbon dioxide gas in aqueous media from colemanite containing arsenic

    Ata, O.N.; Colak, S.; Copur, M.; Celik, C.

    2000-02-01

    The Taguchi method was used to determine optimum conditions for the boric acid extraction from colemanite ore containing As in aqueous media saturated by CO{sub 2} gas. After the parameters were determined to be efficient on the extraction efficiency, the experimental series with two steps were carried out. The chosen experimental parameters for the first series of experiments and their ranges were as follows: (1) reaction temperature, 25--70 C; (2) solid-to-liquid ratio (by weight), 0.091 to 0.333; (3) gas flow rate (in mL/min), 66.70--711; (4) mean particle size, {minus}100 to {minus}10 mesh; (5) stirring speed, 200--600 rpm; (6) reaction time, 10--90 min. The optimum conditions were found to be as follows: reaction temperature, 70 C; solid-to-liquid ratio, 0.091; gas flow rate, 711 (in mL/min); particle size, {minus}100 mesh; stirring speed, 500 rpm; reaction time, 90 min. Under these optimum conditions, the boric acid extraction efficiency from the colemanite containing As was approximately 54%. Chosen experimental parameters for the second series of experiments and their ranges were as follows: (1) reaction temperature, 60--80 C; (2) solid-to-liquid ratio (by weight), 0.1000 to 0.167; (3) gas pressure (in atm), 1.5; 2.7; (4) reaction time, 45--120 min. The optimum conditions were found to be as follows: reaction temperature, 70 C; solid-to-liquid ratio, 0.1; gas pressure, 2.7 atm; reaction time, 120 min. Under these optimum conditions the boric acid extraction efficiency from the colemanite ore was approximately 75%. Under these optimum conditions, the boric acid extraction efficiency from calcined colemanite ore was approximately 99.55%.

  19. Correlation studies of entero-set 20, API 20E and conventional media systems for Enterobacteriaceae identification.

    Aldridge, K E; Hodges, R L

    1981-01-01

    The Entero-Set kit (Fisher Diagnostics) is a 20-biochemical-test system used in the identification of members of the Enterobacteriaceae. This kit was compared with the API 20E (Analytab Products) and conventional media systems, using 505 (303 stock and 202 clinical) strains of Enterobacteriaceae. When the Entero-Set and API 20E results were compared with those of the conventional media system, the Entero-Set performed as well as the API 20E in overall identification. Comparison of common bioc...

  20. Development of partitioning method. Adsorption of cesium with mordenite in acidic media

    Adsorption of cesium with mordenite from a acidic solution, typically from a 0.5 mol/L nitric acid solution, was studied to examine the possibility to design a new separation scheme for partitioning of high-level liquid waste. Batch adsorption experiments showed that three mordenites examined (natural mordenite and two synthetic mordenites Zeolon 900Na and 900H) have very close behavior with the parameters of adsorption kinetics, the saturation capacity by Langmuir equation, the distribution coefficient of Cs and adsorption of other elements. In the Cs adsorption with the natural mordenite at 0.5 mol/L nitric acid, distribution coefficient was 1150 ml/g and the saturation capacity was 0.64 mmol/g. In the adsorption of Cs on column using the natural mordenite, the flow rate of the Cs solution modified only the 5% breakthrough point and gave no influence on the total capacity of Cs. Column experiments with a mixed solution of Cs, Rb, Na, Ba, Sr, Cr, Ni, Ru, Rh and Pd showed that cesium was adsorbed very selectively. Only about 4% of rubidium in a molar ratio were retained in the column. The total quantity of Cs and Rb adsorbed was 0.51 mmol/g at 0.5 mol/L nitric acid. Elution of Cs (and Rb) with 4 mol/L nitric acid was performed against the column of the loaded natural mordenite. The adsorbed Cs and Rb were well eluted, and a good mass balance was obtained between the adsorbed quantity by breakthrough curves and the quantity found in the eluate. (author)

  1. Solvent Extraction of Platinum (IV) with 4-(4-Ethoxybenzylideneamino)-5-methyl-4H-1,2,4-triazole-3-thiol (EBIMTT) from Hydrochloric Acid Media

    The solvent extraction of platinum (IV) metal from hydrochloric acid media using 4-(4-ethoxybenzylide-neamino)-5-methyl-4H-1,2,4-triazole-3-thiol (EBIMTT) in chloroform was studied as a function of several variables, such as reagent, acid and metal ion concentration, effect of various diluents, and diverse ions. The proposed method was further applied for the separation of platinum (IV) from binary mixtures, synthetic mixtures, alloys and commercially available samples

  2. Determination of Amino Acids in Cell Culture and Fermentation Broth Media Using Anion-Exchange Chromatography with Integrated Pulsed Amperometric Detection

    Hanko, Valoran P.; Heckenberg, Andrea; Rohrer, Jeffrey S.

    2004-01-01

    Anion-exchange chromatography with integrated pulsed amperometric detection (AE-IPAD) separates and directly detects amino acids, carbohydrates, alditols, and glycols in the same injection without pre- or post-column derivatization. These separations use a combination of NaOH and NaOH/sodium acetate eluents. We previously published the successful use of this technique, also known as AAA-Direct, to determine free amino acids in cell culture and fermentation broth media. We showed that retentio...

  3. Effect of denaturants on the speciation of dicarboxylic acids: uranium(VI) complexes of oxalic acid in micellar media

    A computer assisted pH-metric investigation has been carried out on the effect of micelles on the complexes of uranium(VI) with oxalic acid. Approximate formation constants have been calculated with the computer program SCPHD utilizing the experimental data obtained by monitoring H+ ion concentration. The formation constants thus obtained are refined with the computer program MINIQUAD75. Selection of the best-fit chemical model is based on the statistical parameters and residual analysis. The major complexes formed are [UO2(C2O4)2]2-, UO2(C2O4) and [UO2(C2O4)2OH]3-. The distribution patterns of the different species with pH show that [UO2(C2O4)2]2- is the predominant species. Influence of the micelles on the speciation is discussed based on the distribution of the various species in the Stern layer and in bulk solvent. The probable structures of the complexes are also given. (author)

  4. Th(IV)-hexacyanoferrate modified carbon paste electrode as a new electrocatalytic probe for simultaneous determination of ascorbic acid and dopamine from acidic media

    Farhadi, Khalil; Kheiri, Farshad [Urmia University (Iran, Islamic Republic of). Faculty of Science. Dept. of Chemistry; Golzan, Mirmaqsoud [Urmia University, Urmia (Iran, Islamic Republic of). Faculty of Science. Dept. of Physics]. E-mail: khfarhadi@yahoo.com

    2008-07-01

    A stable carbon paste electrode (CPE) was prepared with Th(IV)-hexacyanoferrate (Th-HCF) ion pair and its electrochemical behavior was investigated by cyclic voltammetry. The apparent heterogeneous rate constant, k{sub s}, and transfer coefficient, alpha, for electron transfer between Th-HCF ion-pair and CPE were calculated as 3.1 +- 0.1 s{sup -1} and 0.47, respectively. The surface coverage ({gamma}) of the proposed electrode was calculated as 7.06 x 10{sup -10} mol cm{sup -2}. The proposed Th-HCF modified carbon paste electrode (THMCPE) showed a good electrocatalytic behavior with a significant shift toward negative potentials in oxidation of ascorbic acid (AA) and dopamine (DA) in acidic media (phosphate buffer solution, pH 3). The THMCPE exhibited excellent characteristics for simultaneous determination of AA and DA. Amperometric curves using the catalytic currents are linear for DA and AA concentrations in the ranges 8 x 10{sup -6} - 2 x 10{sup -3} and 1 x 10{sup -5} - 2 x 10{sup -3} mol L{sup -1} with detection limits 5.6 x 10{sup -6} mol L{sup -1} and 4.7 x 10{sup -6} mol L{sup -1}, respectively. Diffusion coefficients of AA and DA in electrocatalytic oxidation were calculated from chronoamperometric data. (author)

  5. Th(IV)-hexacyanoferrate modified carbon paste electrode as a new electrocatalytic probe for simultaneous determination of ascorbic acid and dopamine from acidic media

    A stable carbon paste electrode (CPE) was prepared with Th(IV)-hexacyanoferrate (Th-HCF) ion pair and its electrochemical behavior was investigated by cyclic voltammetry. The apparent heterogeneous rate constant, ks, and transfer coefficient, alpha, for electron transfer between Th-HCF ion-pair and CPE were calculated as 3.1 +- 0.1 s-1 and 0.47, respectively. The surface coverage (Γ) of the proposed electrode was calculated as 7.06 x 10-10 mol cm-2. The proposed Th-HCF modified carbon paste electrode (THMCPE) showed a good electrocatalytic behavior with a significant shift toward negative potentials in oxidation of ascorbic acid (AA) and dopamine (DA) in acidic media (phosphate buffer solution, pH 3). The THMCPE exhibited excellent characteristics for simultaneous determination of AA and DA. Amperometric curves using the catalytic currents are linear for DA and AA concentrations in the ranges 8 x 10-6 - 2 x 10-3 and 1 x 10-5 - 2 x 10-3 mol L-1 with detection limits 5.6 x 10-6 mol L-1 and 4.7 x 10-6 mol L-1, respectively. Diffusion coefficients of AA and DA in electrocatalytic oxidation were calculated from chronoamperometric data. (author)

  6. Radiation-chemical behaviour of Rh(3) in perchloric and nitric acid media

    Rhodium(3) behaviour in solutions of concentrated (> 1 mol/l) nitric and perchloric acids under 60Co gamma radiation with dose rate of 3.5 Gy/s has been studied. It is shown that in case of nitrate solution irradiation by doses up to 2x104 Gy, rhodium(3) concentration does not change. Rhodium(3) proved to be stable in perchlorate solutions in case of irradiation by doses up to 3x104 Gy; however, in the presence of organic acids and alcohols its reduction to methane occurred. Kinetic characteristics of rhodium(3) reduction by ethyl alcohol by the doses up to 4x104 Gy have been ascertained, reduction mechanism being considered. 6 refs.; 4 figs.; 1 tab

  7. Interaction study between Ca2+ and humic acids in brine media

    The interaction between Ca2+ and humic acids (HA) was studied at ionic strengths from 0.10 to 5.0 m (NaCl) by the solvent extraction technique. The dependence of the stability constants upon pcH (4.7 to 9.0) was interpreted by the polyelectrolyte model of HA. The data was consistent with formation of a single Ca-HA complex. (orig.)

  8. Optimization of growth media components for polyhydroxyalkanoate (PHA) production from organic acids by Ralstonia eutropha

    Yang, Yung-Hun; Brigham, Christopher J.; Budde, Charles F.; Boccazzi, Paolo; Willis, Laura B.; Hassan, Mohd Ali; Yusof, Zainal Abidin Mohd; Rha, ChoKyun; Sinskey, Anthony J.

    2010-01-01

    We employed systematic mixture analysis to determine optimal levels of acetate, propionate, and butyrate for cell growth and polyhydroxyalkanoate (PHA) production by Ralstonia eutropha H16. Butyrate was the preferred acid for robust cell growth and high PHA production. The 3-hydroxyvalerate content in the resulting PHA depended on the proportion of propionate initially present in the growth medium. The proportion of acetate dramatically affected the final pH of the growth medium. A model was ...

  9. Optimization of media for bioethanol production by Pichia stipitis from sugarcane bagasse pretreated by dilute acid

    Mohsen Ahi; Mehrdad Azin; Seyed Abbas Shojaosadati; Ebrahim Vasheghani Farahani; Mohsen Nosrati

    2014-01-01

    Introduction: Reduction of fossil fuels due to its increasing consumption caused the biofuels production as an important topic, today. Using resources that have not food application was regarded as the second generation biofuels and consisted of lignocelluloses. Since considerable amount of lignocellulosic material are pentoses, utilizing them is important for the production of biofuels. Materials and methods: Sugarcane bagasse was pretreated with dilute acid method. Pichia stipitis was us...

  10. Technetium(VII) extraction with calix[4]arene tetraketones and tetraesters from acid and alkaline media

    Extraction of technetium(VII) and americium(III) by tetrasubstituted by lower edge calix[4]arenes containing carbonyl and ester groups in the cone conformation was studied for choosing extractants for fractionation of liquid radioactive waste produced as a results of nuclear fuel reprocessing. It was established that both types of extractants are selective and highly effective agents for technetium(VII) extraction both from acid and alkaline solutions. Under the conditions studied no extraction of americium(III) takes place

  11. Modeling of dissolution patterns for carbonate acidizing in the porous media

    Samadi, Fereshteh; Esmaeilzadeh, Feridun; Mowla, Dariush

    2012-05-01

    Matrix acidizing is a common technique to stimulate wells for improving well inflow performance. In this treatment that is widely used in the oil industry, acid solution is injected into the formation to dissolve some minerals to increase permeability of carbonate near the wellbore. The aim of the treatment is to create empty channels called wormholes. Wormholing in carbonate rocks is a complex 3-D phenomenon. Matrix acidizing generally should be applied when a well has a high skin factor that cannot be attributed to partial penetration, perforation efficiency or other mechanical aspects of the completion. Obviously, it is of extreme importance to quantify the skin factor to evaluate the effectiveness of stimulation treatments. When wormholes extend beyond the damaged zone or connect with natural fissures in the formation, a negative skin effect is obtained. An ideal matrix treatment restores the permeability in the near wellbore region to a value at least as high as the original undamaged permeability; it accomplishes this over the entire completed interval and it leaves the formation in the treated region with high relative permeability to the oil and/or gas phase. Designing a treatment should strive to achieve this ideal at the lowest possible cost, which requires consideration of the many physical and chemical interactions taking place between the injected fluids and the reservoir minerals and fluids. In this work, a threescale continuum model is used to model reactive dissolution of carbonate rocks in radial flow. Both the Darcy and pore scale physics such as mass transfer of acid molecules to the mineral surface and subsequent reaction at the surface, changing pore structure and variations in reservoir permeability are included in this model. Partial differential equations obtained from the model, have been solved by numerical method. The influence of reservoir temperature on optimum injection rate is investigated. Results show that optimum injection rate

  12. Phosphine and thiophene cyclopalladated complexes: hydrolysis reactions in strong acidic media.

    García, Begoña; Hoyuelos, Francisco J; Ibeas, Saturnino; Muñoz, María S; Navarro, Ana M; Peñacoba, Indalecio A; Leal, José M

    2010-12-01

    The mechanisms for the hydrolysis of organopalladium complexes [Pd(CNN)R]BF(4) (R=P(OPh)(3), PPh(3), and SC(4)H(8)) were investigated at 25 °C by using UV/Vis absorbance measurements in 10 % v/v ethanol/water mixtures containing different sulphuric acid concentrations in the 1.3-11.7 M range. In all cases, a biphasic behavior was observed with rate constants k(1obs), which corresponds to the initial step of the hydrolysis reaction, and k(2obs), where k(1obs)>k(2obs). The plots of k(1obs) and k(2obs) versus sulfuric acid concentration suggest a change in the reaction mechanism. The change with respect to the k(1obs) value corresponds to 35 %, 2 %, and 99 % of the protonated complexes for R=PPh(3), P(OPh)(3), and SC(4)H(8), respectively. Regarding k(2obs), the change occurred in all cases at about 6.5 M H(2)SO(4) and matched up with the results reported for the hydrolysis of the 2-acetylpyridinephenylhydrazone (CNN) ligand. By using the excess acidity method, the mechanisms were elucidated by carefully looking at the variation of k(i),(obs) (i=1,2) versus cH+. The rate-determining constants, k(0,A-1), k(0,A-2), and k(0,A-SE2) were evaluated in all cases. The R=P(OPh)(3) complex was most reactive due to its π-acid character, which favors the rupture of the trans nitrogen-palladium bond in the A-2 mechanism and also that of the pyridine nitrogen-palladium bond in the A-1 mechanism. The organometallic bond exerts no effect on the relative basicity of the complexes, which are strongly reliant on the substituent. PMID:21125574

  13. Phosphotungstic Acid Catalyzed One-Pot Synthesis of 2-amino-3,5-dicarbonitrile-6-thio-pyridines in Aqueous Media

    In this study, we report the one-pot synthesis of 2-amino-3,5-dicarbonitrile-6-thio-pyridines with benzaldehyde, malononitrile, and thiophenol by using phosphotungstic acid as an efficient catalyst to aqueous media. This method has the advantages of easy separation, high storage stability, and environmental friendliness. (author)

  14. Elution of nickel ions from alginate beads in an acid media

    Elution of nickel ions from alginate beads was studied in a temperature range of 2 to 80 degree centigrade and a sulfuric acid concentration between 0.005 to 2.5 g L-1. The elution mechanism was established by ion exchange between nickel and ions protons, obtaining a value of 93% elution at a temperature of 80 degree centigrade and a H2SO4 concentration of 0.25 g L-1. The influence of other acids on nickel elution was also studied. The nickel elution rate was significantly influenced by temperature and concentration of H2SO4. Elution kinetics of nickel ions was studied, and the 1-(1-α)1/3=kappt model properly described the kinetics of this reaction. The dependence of nickel elution on the sulfuric acid concentration was of the order of 0.33. Moreover, the intrinsic rate constants were determined and an activation energy value of 54.5 kJ mol-1 was obtained for the temperature range studied. The results indicated that the nickel elution is a process controlled by chemical reactions. (Author)

  15. Review and assessment of technologies for the separation of cesium from acidic media

    A preliminary literature survey has been conducted to identify and evaluate methods for the separation of cesium from acidic waste. The most promising solvent extraction, precipitation, and ion exchange methods, along with some of the attributes for each method, are listed. The main criteria used in evaluating the separation methods were as follows: (1) good potential for cesium separation must be demonstrated (i.e., cesium decontamination factors on the order of 50 to 100). (2) Good selectivity for cesium over bulk components must be demonstrated. (3) The method must show promise for evolving into a practical and fairly simple process. (4) The process should be safe to operate. (5) The method must be robust (i.e., capable of separating cesium from various acidic waste types). (6) Secondary waste generation must be minimized. (7) The method must show resistance to radiation damage. The most promising separation methods did not necessarily satisfy all of the above criteria, thus key areas requiring further development are suggested for each method. The report discusses in detail these and other areas requiring further development, as well as alternative solvent extraction, precipitation, ion exchange, and open-quote other close-quote technologies that, based on current information, show less promise for the separation of cesium from acidic wastes because of significant process limitations. When appropriate, the report recommends areas of future development

  16. Electro-oxidation of methanol on mixed catalysts based on platinum and organic metal complexes in acidic media

    New electro-catalysts were developed based on platinum and organic metal complexes for methanol oxidation reaction (MOR) in acidic media. As complexes nitrogen containing ligands such as N,N'-bis(salicylidene)ethylenediamine (salen), N,N'-bis(salicylidene)phenylenediamine (salophen), N,N'-mono-8-quinolyl-o-phenylenediamine (mqph) and N,N'-bis(anthranilidene)ethylenediamine (anthen), coordinated to V, Mn, Fe, Co, Ni, Cu, Mo, Pd and Sn were synthesized and tested. Mixture of platinum tetraammine complex with one of the organic metal complexes with 50/50 mixing ratio was supported on carbon powder, and heat-treated at 400-700 deg. C in argon atmosphere. Powder, thus obtained was put on a glassy carbon disk electrode, and tested for electrochemical MOR in sulfuric acid solutions. Among catalysts tested, Fe(salen), VO(salen), Ni(mqph) or Pd(mqph) turned out to be good co-catalysts mixed with Pt for MOR. Compared with platinum-ruthenium alloy catalysts, the new catalysts showed very promising catalytic ability. It is inferred that after the heat treatment, the organic complex catalyst played a role in mitigating CO poisoning on Pt surface

  17. Color reactions between indium and reagents of chromotropic acid 2,7-bisazo substituted derivatives in water - organic media

    Colour reactions between indium and six 2,7-bisazo substituted chromotropic acid derivatives have been studied in organo-aqueous solutions containing propanol and isopropanol. The reactions between indium and picramin S or picramin M in the organo-aqueous solutions are more sensitive and contrast than in aqueous media. New highly sensitive reactions for the reagents, whose benzene rings contain carboxy groups, have been found. Significant amounts of some complexing substances and acids do not interfere with the reaction between indium and picramin M although their application does not improve the reaction selectivity. The selectivity can be dramatically improved if the reaction proceeds directly in an organic extract after indium extraction by diisopropyl ether from a solution containing H2SO4 and KI. The possibility has been shown of photometric determining indium in gallium compounds using a model mixture of In and Ga (1:2400). Multiple by mass quantities of Ga (3700), Ca (3600), Fe (2500), Al (1700) do not interfere with indium determination

  18. Extraction and separation of U(VI and Th(IV from hydrobromic acid media using Cyanex-923 extractant

    Ghag Snehal M.

    2010-01-01

    Full Text Available A systematic study of the solvent extraction of uranium(VI and thorium(IV from hydrobromic acid media was performed using the neutral phosphine oxide extractant Cyanex-923 in toluene. These metal ions were found to be quantitatively extracted with Cyanex-923 in toluene in the acidity range 5x10-5-1x10-4 M and 5x10-5-5x10-3 M, respectively, and they are stripped from the organic phase with 7.0 M HClO4 and 2.0- 4.0 M HCl, respectively. The effect of the equilibrium period, diluents, diverse ions and stripping agent on the extraction of U(VI and Th(IV was studied. The stoichiometry of the extracted species of these metal ions was determined based on the slope analysis method. The extraction reactions proceed by solvation and their probable extracted species found in the organic phase were UO2Br2•2Cyanex-923 and ThBr4•2Cyanex-923. Based on these results, a sequential procedure for their separation from each other was developed.

  19. Separation and immobilization of Sr and Cs contained in acidic media by using inorganic ion-exchangers. Literature survey

    Yamagishi, Isao [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    2001-07-01

    The present study deals with the survey of inorganic ion-exchangers suitable for separation and immobilization of Sr and Cs contained in acidic high-level liquid waste. The stabilities of published waste forms and their preparation processes were evaluated from the standpoint of conversion of exchangers containing Sr and Cs into appropriate waste forms. The essential results are below. (1) For separation and immobilization of Cs, crystalline silicotitanate seems to be the most promising exchanger. Insoluble ferrocyanides and phosphates are not suitable for immobilization without additives. Mordenite is inexpensive and commercially available but it would dissolve in highly acidic media. (2) For selective separation of Sr, there is no promising exchanger up to now. It is necessary either to modify separation condition or to synthesize a novel exchanger. (3) Soluble salts, glasses and ceramics are proposed as a storage or disposal form of separated Sr and Cs. Ceramics sintered by hot-pressing are favorable waste forms of inorganic ion-exchangers but their leachabilities and thermal conductivities are largely influenced by qualities of products. Crystallinity of a sintered exchanger depends on its composition. Exchanges of low Cs contents are often converted into amorphous materials whose chemical stabilities depend on solubilities of components of exchangers. (4) A new exchanger to be synthesized is crystalline and selective toward Sr and Cs. One meq/g is enough for Sr and Cs capacities, which are restricted by thermal and transmutation effects. Composition of the exchanger should be selected from the point of a scenario of separation and disposal. The solubilities of SiO{sub 2}, TiO{sub 2}, ZrO{sub 2}, Nb{sub 2}O{sub 5} and Ta{sub 2}O{sub 5} are low in acidic media and those of Al{sub 2}O{sub 3}, TiO{sub 2} and ZrO{sub 2}, in disposal circumstances. (5) Future works are optimization of separation scheme including development of exchangers, simplification of

  20. Solvent extraction of palladium with di-n-hexyl sulfide from hydrochloric acid media

    Lee, Jae-Chun; Jeong, Jin-Ki; Park, Jin-Tae [Korea Institute of Geology Mining and Materials, Taejeon (Korea); Kim, Weol-Jung; Rhim, Ji-Won [Hannam University, Taejeon(Korea)

    2000-06-30

    The solvent extraction of palladium from aqueous chloride media was carried out using di-n-hexyl sulfide(DHS) known as a selective extractant for palladium. The effects of the concentrations of extractant, palladium, Cl{sup -}, NO{sub 3}{sup -}, and HCl on the palladium extraction were investigated. Also, The effects of NH{sub 4}OH concentration, contact time, and the addition of NH{sub 4}Cl were examined in the stripping of palladium from the organic phase with NH{sub 4}OH solution. The result shows that palladium was extracted as PdCl{sub 2}{center_dot}2DHS. The initial rates of palladium extraction decreased with the increase of HCl and NO{sub 3}{sup -} concentrations in the aqueous phase. The extraction of palladium with DHS was endothermic with {delta}H{sup o} of -65.6 kJ/mol which the distribution coefficient increased with temperature. Palladium in the organic phase was completely stripped with NH{sub 4}OH solution. (author). 13 refs., 11 figs.

  1. Correlating multidimensional fetal heart rate variability analysis with acid-base balance at birth

    Fetal monitoring during labour currently fails to accurately detect acidemia. We developed a method to assess the multidimensional properties of fetal heart rate variability (fHRV) from trans-abdominal fetal electrocardiogram (fECG) during labour. We aimed to assess this novel bioinformatics approach for correlation between fHRV and neonatal pH or base excess (BE) at birth. We enrolled a prospective pilot cohort of uncomplicated singleton pregnancies at 38–42 weeks’ gestation in Milan, Italy, and Liverpool, UK. Fetal monitoring was performed by standard cardiotocography. Simultaneously, with fECG (high sampling frequency) was recorded. To ensure clinician blinding, fECG information was not displayed. Data from the last 60 min preceding onset of second-stage labour were analyzed using clinically validated continuous individualized multiorgan variability analysis (CIMVA) software in 5 min overlapping windows. CIMVA allows simultaneous calculation of 101 fHRV measures across five fHRV signal analysis domains. We validated our mathematical prediction model internally with 80:20 cross-validation split, comparing results to cord pH and BE at birth. The cohort consisted of 60 women with neonatal pH values at birth ranging from 7.44 to 6.99 and BE from −0.3 to −18.7 mmol L−1. Our model predicted pH from 30 fHRV measures (R2 = 0.90, P < 0.001) and BE from 21 fHRV measures (R2 = 0.77, P < 0.001). Novel bioinformatics approach (CIMVA) applied to fHRV derived from trans-abdominal fECG during labor correlated well with acid-base balance at birth. Further refinement and validation in larger cohorts are needed. These new measurements of fHRV might offer a new opportunity to predict fetal acid-base balance at birth. (fast track communication)

  2. Maternal fatty acid desaturase genotype correlates with infant immune responses at 6 months.

    Muc, Magdalena; Kreiner-Møller, Eskil; Larsen, Jeppe M; Birch, Sune; Brix, Susanne; Bisgaard, Hans; Lauritzen, Lotte

    2015-09-28

    Breast milk long-chain PUFA (LCPUFA) have been associated with changes in early life immune responses and may modulate T-cell function in infancy. We studied the effect of maternal fatty acid desaturase (FADS) genotype and breast milk LCPUFA levels on infants' blood T-cell profiles and ex vivo-produced cytokines after anti-CD3/CD28 stimulation of peripheral blood mononuclear cells in 6-month-old infants from the Copenhagen Prospective Study of Asthma in Childhood birth cohort. LCPUFA concentrations of breast milk were assessed at 4 weeks of age, and FADS SNP were determined in both mothers and infants (n 109). In general, breast milk arachidonic acid (AA) levels were inversely correlated with the production of IL-10 (r -0.25; P=0.004), IL-17 (r -0.24; P=0.005), IL-5 (r -0.21; P=0.014) and IL-13 (r -0.17; P=0.047), whereas EPA was positively correlated with the counts of blood regulatory T-cells and cytotoxic T-cells and decreased T-helper cell counts. The minor FADS alleles were associated with lower breast milk AA and EPA, and infants of mothers carrying the minor allele of FADS SNP rs174556 had higher production of IL-10 (r -0.23; P=0.018), IL-17 (r -0.25; P=0.009) and IL-5 (r -0.21; P=0.038) from ex vivo-activated immune cells. We observed no association between T-cell distribution and maternal or infant FADS gene variants. We conclude that increased maternal LCPUFA synthesis and breast milk AA are associated with decreased levels of IL-5, IL-13 (type-2 related), IL-17 (type-17 related) and IL-10 (regulatory immune responses), but not with interferon-γ and TNF-α, which could be due to an effect of the maternal FADS variants on the offspring immune response transferred via breast milk LCPUFA. PMID:26283408

  3. The implications of particle energy and acidic media on gross alpha and gross beta determination using liquid scintillation

    Zapata-Garcia, D. [Laboratori de Radiologia Ambiental (LRA), Departament de Quimica Analitica, Universitat de Barcelona, Marti i Franques, 1-11 Planta 3, E-08028 Barcelona (Spain); Llaurado, M., E-mail: montse.llaurado@ub.edu [Laboratori de Radiologia Ambiental (LRA), Departament de Quimica Analitica, Universitat de Barcelona, Marti i Franques, 1-11 Planta 3, E-08028 Barcelona (Spain); Rauret, G. [Laboratori de Radiologia Ambiental (LRA), Departament de Quimica Analitica, Universitat de Barcelona, Marti i Franques, 1-11 Planta 3, E-08028 Barcelona (Spain)

    2012-04-15

    The interaction of humans with radioactivity present in the environment from natural and artificial sources necessitates an evaluation of its risk on human health. Gross alpha and gross beta activities can provide a rapid evaluation of the radioactive content of a sample and can be simultaneously determined by using liquid scintillation counters. However, calibration of the liquid scintillation counter is required and is affected by many factors, such as particle energy and the acidity of the media. This study investigates what effect the particle energy used for calibration has on misclassification and how to account for this misclassification in routine measurements. The variability in measurement produced by the final pH, as well as any acids used in sample treatment, was also studied. These results showed that the most commonly used acid for these types of analyses, HNO{sub 3}, produced a high amount of misclassifications at very low pH. The results improved when HCl was used to adjust the sample to low pH. - Highlights: Black-Right-Pointing-Pointer We study the effect of alpha and beta energies on PSA optimisation. Black-Right-Pointing-Pointer The optimum PSA shifts to higher values as the alpha energy increases. Beta energies do not affect it. Black-Right-Pointing-Pointer We study the effect of pH on the simultaneous determination of gross alpha/beta activities. Black-Right-Pointing-Pointer HNO{sub 3} produces a high amount of misclassification at very low pH. Black-Right-Pointing-Pointer The results improve when HCl is used to adjust the sample to low pH.

  4. Influence of poly(aminoquinone) on corrosion inhibition of iron in acid media

    Jeyaprabha, C.; Sathiyanarayanan, S.; Phani, K. L. N.; Venkatachari, G.

    2005-11-01

    The inhibitor performance of chemically synthesized water soluble poly(aminoquinone) (PAQ) on iron corrosion in 0.5 M sulphuric acid was studied in relation to inhibitor concentration using potentiodynamic polarization and electrochemical impedance spectroscopy measurements. On comparing the inhibition performance of PAQ with that of the monomer o-phenylenediamine (OPD), the OPD gave an efficiency of 80% for 1000 ppm while it was 90% for 100 ppm of PAQ. PAQ was found to be a mixed inhibitor. Besides, PAQ was able to improve the passivation tendency of iron in 0.5 M H 2SO 4 markedly.

  5. Macro level extraction of U(VI) and Pu(IV) by tri-iso-amyl phosphate and tri-n-butyl phosphate from nitric acid media

    Batch extraction of Pu(IV) by 1.1 M Tri-iso-amyl phosphate (TiAP) in n-dodecane (DD) from plutonium nitrate solutions in nitric acid media has been investigated as a function of metal loading and equilibrium aqueous phase acidity at 303 K under high solvent loading conditions. Co-extraction behavior of U(VI) and Pu(IV) with 1.1 M solutions of trialkyl phosphates (TBP and TiAP) in n-DD from nitric acid media has also been compared by carrying out the extraction from a U-Pu feed solution (21% Pu to mimic PFBR MOX fuel composition) at 303 K. (author)

  6. Novel additives for accelerating radiation grafting of monomers to polymers in acid media

    Mineral acid and polyfunctional monomers in additive amounts (1% v/v) are shown to act synergistically in enhancing radiation grafting yields for a typical system involving the copolymerization of styrene in methanol to the polyolefins. Polyethylene and polypropylene films have been used as representative backbone polymers with divinylbenzene and trimethylolpropane triacrylate as typical polyfunctionals in the current work. The effect of dose rate on the copolymerization yield is reported. Grafting efficiency is shown to be enhanced in the presence of both additives. A theory for the role of additives is proposed. The synergistic effect also operates with polypropylene powder. Such an observation is shown to be important in applications of these copolymers for enzyme immobilization, heterogenization of catalytically active homogeneous metal complexes, insolubilization of analytical reagents and art restoration. (author)

  7. Extraction of metals and/or metalloids from acidic media using supercritical fluids and salts

    A method is described for extracting metalloid and metal species from a solid or liquid material by exposing the material to a fluid solvent, particularly supercritical carbon dioxide, containing a chelating agent. The chelating agent forms chelates that are soluble in the fluid to allow removal of the species from the material. In preferred embodiments, the extraction solvent is supercritical carbon dioxide and the chelating agent comprises a trialkyl phosphate, a triaryl phosphate, a trialkylphosphine oxide, a triarylphosphine oxide, or mixtures thereof. The method provides an environmentally benign process for removing contaminants from industrial waste. The method is particularly useful for extracting actinides from acidic solutions, and the process can be aided by the addition of nitrate salts. The chelate and supercritical fluid can be regenerated, and the contaminant species recovered, to provide an economic, efficient process. 7 figs

  8. Evaluation of ability of ferulic acid to control growth and fumonisin production of Fusarium verticillioides and Fusarium proliferatum on maize based media.

    Ferrochio, Laura; Cendoya, Eugenia; Farnochi, María Cecilia; Massad, Walter; Ramirez, María Laura

    2013-10-15

    The aim of this study was to evaluate the efficacy of ferulic acid (1, 10, 20 and 25 mM) at different water activity (aw) values (0.99, 0.98, 0.96 and 0.93) at 25 °C on growth and fumonisin production by Fusarium verticillioides and Fusarium proliferatum on maize based media. For both Fusarium species, the lag phase significantly decreased (p ≤ 0.001), and the growth rates increased (p ≤ 0.001) at the lowest ferulic acid concentration used (1mM), regardless of the aw. However, high doses of ferulic acid (10 to 25 mM) significantly reduced (p ≤ 0.001) the growth rate of both Fusarium species, regardless of the a(w). In general, growth rate inhibition increased as ferulic acid doses increased and as media aw decreased. Fumonisin production profiles of both Fusarium species showed that low ferulic acid concentrations (1-10mM) significantly increased (p ≤ 0.001) toxin production, regardless of the aw. High doses of ferulic acid (20-25 mM) reduced fumonisin production, in comparison with the controls, by both Fusarium species but they were not statistically significant in most cases. The results show that the use of ferulic acid as a post-harvest strategy to reduce mycotoxin accumulation on maize needs to be discussed. PMID:24140805

  9. Correlation of acid-base properties of substituted polystyrene-azo-pyrocatechol and characteristics of their chelates with zirconium

    Acid-base and complexing properties of new synthesized polymeric chelate-forming sorbents (PCS) - substituents of polystyrene-azo-pyrocatechol - are investigated and quantitative correlations between pKOH of functional analytical group (FAG) of sorbent and Hammet constants for para-substituent and ΔpKOH-ΔpK50 correlations of zirconium chelate-forming and pKOH-lgKstb (Kstb - constant of stability of PCS complexes with zirconium) of polychelates to study regularities of effect of peculiarities of structure and acid-base properties of FAG on parameters of zirconium chemical sorption. Established correlations make it possible to predict quantitative physicochemical parameters of sorbents and zirconium chemisorption process with the aim of directed synthesis and application of PCS in concentrating processes

  10. Dissolution of plutonium dioxide in nitric acid media by silver(II) electroreduction

    Oxidative dissolution of plutonium dioxide with electrogenerated silver(II) was undertaken first on an analytical scale in order to discover the parameters controlling this dissolution process and to prove the feasibility of the technique for 300 grams of material. The influence on the rate of PuO2 dissolution of the following parameters was studied: mass of PuO2, current density, total concentration of silver ion, nitric acid concentration, temperature, and agitation efficiency. The results demonstrate that: 1. the limiting step of the dissolution process is the electrogeneration of silver(II); 2. the dissolution of PuO2 can be achieved with a good current efficiency; 3. the best temperature range is 30±100C; 4. the optimum [HNO3] is 4 to 6 M; 5. the plutonium(VI) solution up to 500 g l-1 can be prepared. A six litres capacity thermostated glass electrolyser was built which consists of two separated compartments inlcuding: 1. an anodic compartment equipped with a cylindrical platinum grid electrode (area, 1000 cm2) and a tantalum propeller, and 2. a cathodic compartment of 0.2 litre capacity consisting of an aluminium silicate diaphragm with a tantalum rod cathode. Quantitative dissolutions of 300 g of PuO2 in 4 M HNO3 were performed for 2 h at an applied current of 60 A. (orig.)

  11. Recovery of zinc and manganese from spent batteries by reductive leaching in acidic media

    Buzatu, M.; Săceanu, S.; Petrescu, M. I.; Ghica, G. V.; Buzatu, T.

    2014-02-01

    A systematic investigation has been carried out on the influence of the acid leaching process parameters on the simultaneous metal recovery (Zn and Mn) from the electrode paste of spent alkaline Zn-MnO2 and spent Zn-C batteries. By introducing a reducing agent namely 30% H2O2 in the H2SO4 leaching solution the extraction efficiency for Mn was increased from 43.5% (no addition of H2O2) up to 97.54% (50% excess H2O2 in comparison with the required stoichiometric amount of H2O2). This H2O2 addition proved to have no influence on Zn extraction efficiency which kept constant at a high level (∼98.4%). A less important influence has been noticed for the molar concentration of H2SO4 in the leaching solution. In the range 0.5 M up to 2 M molar concentration of H2SO4 the extraction efficiency was increased from 78.2% up to 98.4% for Zn and from 63.1% up to 97.2% for Mn. Leaching time up to 60 min proved to gradually increase the extraction efficiency up to 96% for Mn and 98% for Zn but further time increase has no more influence. An attempt has been made to recover the carbon from the leaching residue but its structural characterization is still required.

  12. Optimization of media for bioethanol production by Pichia stipitis from sugarcane bagasse pretreated by dilute acid

    Mohsen Ahi

    2014-04-01

    Full Text Available Introduction: Reduction of fossil fuels due to its increasing consumption caused the biofuels production as an important topic, today. Using resources that have not food application was regarded as the second generation biofuels and consisted of lignocelluloses. Since considerable amount of lignocellulosic material are pentoses, utilizing them is important for the production of biofuels. Materials and methods: Sugarcane bagasse was pretreated with dilute acid method. Pichia stipitis was used for the fermentation of released sugars. A L27 Taguchi orthogonal array was considered to optimize the fermentation process and increase the amount of ethanol. The eight factors with three levels considering nitrogen, phosphorus, zinc, sulfur, magnesium, and vitamins sources were considered in this study. Results: The analysis of the results shows that corn steep liquor, ammonium hydrogen phosphate, potassium di-hydrogen phosphate and magnesium sulfate have a significant effect on the production of ethanol, respectively. Confirmation of the optimal conditions shows that ethanol production was increased 97% relative to the mean of the observed results. The yield and productivity during 48 h of the fermentation were reached to 0.26 (g ethanol/g consumed sugar and 0.125g (L.h, respectively. Discussion and conclusion: At the optimum condition the production of ethanol from sugarcane bagasse hydrolysate had higher efficiency relative to previous studies. Results of medium optimization considering cheap resources showed showed an excellent potential toward an economical bioethanol production process.

  13. Corrosion behaviour of WC-Co based hardmetal in neutral chloride and acid sulphate media

    Bozzini, B.; Serra, M.; Fanigliulo, A.; Bogani, F. [Lecce Univ. (Italy). Dipt. di Ingegneria dell' Innovazione; Gaudenzi, G.P. de [Harditalia s.r.l. (OMCD Group), Genova (Italy)

    2002-05-01

    A comparative study of the corrosion behaviour of WC-Co based hardmetals with Ni and Cr{sub 3}C{sub 2} additions is carried out. The aggressive environments are neutral and acidic aerated aqueous solutions of NaCl and H{sub 2}SO{sub 4}. This study is based on electrochemical (linear sweep voltammery), compositional (surface EDX analyses, AAS analyses of attack solutions), structural (XRD) and morphological (SEM) investigations. Electrochemical figures of merit were computed from linear sweep voltammograms in order to rank the corrosion behaviour close to free-immersion conditions in the studied environments and with presence of oxidising agents. EDX and XRD analyses allow to accurately characterise the penetration depth of the attack as well as the preferential dissolution of the constituents. Binders containing Ni show a significantly improved corrosion resistance in the studied systems. The amount of Ni in the binder is the single most important factor affecting corrosion performance. Cr{sub 3}C{sub 2} additions to hardmetals with lower-Ni binders cannot balance the effect of Ni, but give an improved resistance in neutral chloride-containing solutions. (orig.)

  14. Kinetics study on separation of cadmium from tellurium in acidic solution media using ion-exchange resins

    The feasibility of using ion-exchange resins to separate cadmium from tellurium in acidic solutions of the two metals was investigated. We studied the competitive adsorption of cadmium and tellurium in such resins under varying acid strengths and contact time. We found that low sulfuric acid strength (i.e., 0.5 M) was most effective in removing cadmium from solutions. Different ion-exchange resins were tested for their affinity for cadmium and tellurium ions. In the selected systems, the ion-exchange rate of cadmium was rapid in the first 20 min, and reached equilibrium within 2 h. The Lagergren first-order model described the kinetic data with high coefficient of determination and correlation values. At room temperatures the ion-exchange for cadmium onto the resin followed the Freundlich isotherm model. The maximum removal of cadmium obtained from batch studies using resin A was 91%. Column studies with the same resin showed a removal of cadmium of 99.99% or higher

  15. Docosahexaenoic acid ester degradation measured by FTIR-ATR with correlation spectroscopy

    Highly unsaturated fatty acids such as docosahexaenoic acid and linolenic acid are prone to oxidation with a resulting loss of bioactivity and generation of malodorous degradation compounds. Degradation proceeds by formation of the corresponding hydroperoxyl free radical with subsequent oxidative cl...

  16. Breast milk docosahexaenoic acid (DHA) correlates with DHA status of malnourished infants

    Smit, EN; Oelen, EA; Seerat, E; Muskiet, FAJ; Boersma, ER

    2000-01-01

    Aim-To investigate whether low docosahexaenoic acid (22:6 omega 3; DHA) status of malnourished, mostly breast fed infants is a result of low omega 3 fatty acid intake via breast milk. Methods-Fatty acid composition of breast milk of eight Pakistani mothers, and of the erythrocytes of their malnouris

  17. Correlating Mineralogy and Amino Acid Contents of Milligram-Scale Murchison Carbonaceous Chondrite Samples

    Burton, Aaron, S.; Berger, Eve L.; Locke, Darren R.; Elsila, Jamie E.; Glavin, Daniel P.; Dworkin, Jason P.

    2015-01-01

    Amino acids, the building blocks of proteins, have been found to be indigenous in most of the carbonaceous chondrite groups. The abundances of amino acids, as well as their structural, enantiomeric and isotopic compositions differ significantly among meteorites of different groups and petrologic types. This suggests that there is a link between parent-body conditions, mineralogy and the synthesis and preservation of amino acids (and likely other organic molecules). However, elucidating specific causes for the observed differences in amino acid composition has proven extremely challenging because samples analyzed for amino acids are typically much larger ((is) approximately 100 mg powders) than the scale at which meteorite heterogeneity is observed (sub mm-scale differences, (is) approximately 1-mg or smaller samples). Thus, the effects of differences in mineralogy on amino acid abundances could not be easily discerned. Recent advances in the sensitivity of instrumentation have made possible the analysis of smaller samples for amino acids, enabling a new approach to investigate the link between mineralogical con-text and amino acid compositions/abundances in meteorites. Through coordinated mineral separation, mineral characterization and highly sensitive amino acid analyses, we have performed preliminary investigations into the relationship between meteorite mineralogy and amino acid composition. By linking amino acid data to mineralogy, we have started to identify amino acid-bearing mineral phases in different carbonaceous meteorites. The methodology and results of analyses performed on the Murchison meteorite are presented here.

  18. Correlation between seed size, protein and oil contents, and fatty acid composition in soybean genotypes

    Maestri, Damián M.

    1998-12-01

    Full Text Available Eighteen soybean genotypes (Glycine max (L. Merrill with maturity groups IV, V, VI or VII were grown in 1995/96 at the Estación Experimental Agropecuaria (EEA-INTA of Manfredi and Marcos Juárez, Argentina. The aim of this research was to determine possible associations between seed size, protein and oil contents, and fatty composition. Seed size varied between 13.9-21.0 g/100 seeds. Protein and oil contents ranged from 331 to 448 and from 198 to 267 g kg-1, respectively, and showed no significant correlation with seed size. There were significant correlations between seed size and individual fatty adds: positive with stearic and oleic and negative with linoleic. The results obtained suggest that seed size and its relationship with individual fatty acids must be considered in soybean breeding programs.

    Se analizaron 18 genotipos de soja (Glycine max (L. Merrill con grupos de madurez IV, V, VI o VIl, cultivados en 1995/96 en la Estación Experimental Agropecuaria (EEA-INTA de Manfredi y Marcos Juárez, Argentina. El propósito de la investigación fue determinar posibles asociaciones entre el tamaño del grano, los contenidos de proteínas y aceite y la composición de ácidos grasos del mismo. El tamaño del grano varió entre 13.9-21.0 g/100 granos. Los porcentajes de proteínas y aceite estuvieron comprendidos entre 331-448 y entre 198-267 g kg-1 respectivamente, y no mostraron correlaciones significativas con el tamaño del grano. Se observaron correlaciones significativas entre el tamaño del grano y determinados ácidos grasos: positivas con esteárico y oleico y negativa con linoleico. Las asociaciones encontradas podrían ser de utilidad en programas de mejoramiento de soja.

  19. On the relationship between corrosion inhibiting effect and molecular structure of 2,5-bis(n-pyridyl)-1,3,4-thiadiazole derivatives in acidic media: Ac impedance and DFT studies

    Bentiss, F., E-mail: fbentiss@enscl.f [Laboratoire de Chimie de Coordination et d' Analytique (LCCA), Faculte des Sciences, Universite Chouaib Doukkali, B.P. 20, M-24000 El Jadida (Morocco); Mernari, B. [Laboratoire de Chimie de Coordination et d' Analytique (LCCA), Faculte des Sciences, Universite Chouaib Doukkali, B.P. 20, M-24000 El Jadida (Morocco); Traisnel, M. [Unite Materiaux et Transformations (UMET), Ingenierie des Systemes Polymeres, CNRS UMR 8207, ENSCL, B.P. 90108, F-59652 Villeneuve d' Ascq Cedex (France); Vezin, H. [Laboratoire de Spectrochimie Infrarouge et Raman (LASIR), UMR-CNRS 8516, Universite des Sciences et Technologies de Lille, Batiment C5, F-59655 Villeneuve d' Ascq Cedex (France); Lagrenee, M., E-mail: michel.lagrenee@ensc-lille.f [Unite de Catalyse et de Chimie du Solide (UCCS), UMR-CNRS 8181, ENSCL, B.P. 90108, F-59652 Villeneuve d' Ascq Cedex (France)

    2011-01-15

    Research highlights: {yields}2,5-Bis(n-pyridyl)-1,3,4-thiadiazoles (n-PTH) act as good inhibitors for the mild steel in acidic media. {yields}The inhibiting protection depends on the position of the nitrogen on the pyridinium substituent according to order 3-PTH > 2-PTH > 4-PTH. {yields}The adsorption of n-PTH is found to follow the Langmuir's adsorption isotherm. {yields}Data obtained from quantum chemical calculations using DFT method were correlated to the experimentally obtained inhibition efficiencies. - Abstract: The inhibition properties of 2,5-bis(n-pyridyl)-1,3,4-thiadiazoles (n-PTH) on corrosion of mild steel in different acidic media (1 M HCl, 0.5 M H{sub 2}SO{sub 4} and 1 M HClO{sub 4}) were analyzed by electrochemical impedance spectroscopy (EIS). The n-PTH derivatives exhibit good inhibition properties in different acidic solutions and the calculated values of {Delta}G{sub ads}{sup 0} revealed that the adsorption mechanism of n-PTH on steel surface is mainly due to chemisorption. While in 1 M HClO{sub 4}, both 2-PTH and 4-PTH isomers stimulate the corrosion process especially at low concentrations. Quantum chemical calculations using the density functional theory (DFT) were performed on n-PTH derivatives to determine the relationship between molecular structure and their inhibition efficiencies. The results of the quantum chemical calculations and experimental inhibition efficiency were subjected to correlation analysis and indicate that the inhibition effects of n-PTH may be explained in terms of electronic properties.

  20. Myocardial damage assessed by indium-111-antimyosin: correlation with persistent enteroviral ribonucleic acid in dilated cardiomyopathy

    The persistence of enteroviral ribonucleic acid (RNA) in the myocardium has been implicated as a pathogenetic factor in idiopathic dilated cardiomyopathy. Enteroviral persistence may lead to myocardial cell membrane damage, resulting in increased uptake of antimyosin antibodies. To further evaluate this hypothesis, a direct comparison of myocardial antimyosin uptake with the presence of enteroviral RNA was performed in ten patients (one female, nine male; 53±8 years) with chronic dilated cardiomyopathy. Planar antimyosin images were obtained 48 h after the injection of indium-111-labelled antimyosin Fab. Using a region of interest technique, the heart to lung uptake ratio (HLR) was calculated as a semiquantitative parameter of myocardial tracer uptake. Cardiac catheterization was performed to assess left ventricular function and to obtain myocardial biopsy samples. In the biopsy samples, gene amplification by polymerase chain reaction (PCR) was used to specifically detect enteroviral RNA. In the ten patients, the left ventricular ejection fraction was 39%±11% and the end-diastolic volume 131±46 ml/m2. The HLR was 1.72±0.21 and showed no correlation with functional parameters. In two patients with a positive PCR consistent with persisting enteroviral RNA, the HLR was not higher than that in eight patients with a negative PCR (1.46±0.18 vs 1.78±0.18, respectively). These results suggest that increased uptake of 111In-antimyosin in chronic idiopathic dilated cardiomyopathy cannot be explained by pure persistence of enteroviral RNA. Other pathogenetic factors such as myocardial autoantibodies or microvascular spasm may be responsible for myocyte membrane damage detected by antimyosin. (orig.). With 3 figs., 1 tab

  1. Correlating multidimensional fetal heart rate variability analysis with acid-base balance at birth.

    Frasch, Martin G; Xu, Yawen; Stampalija, Tamara; Durosier, Lucien D; Herry, Christophe; Wang, Xiaogang; Casati, Daniela; Seely, Andrew Je; Alfirevic, Zarko; Gao, Xin; Ferrazzi, Enrico

    2014-12-01

    Fetal monitoring during labour currently fails to accurately detect acidemia. We developed a method to assess the multidimensional properties of fetal heart rate variability (fHRV) from trans-abdominal fetal electrocardiogram (fECG) during labour. We aimed to assess this novel bioinformatics approach for correlation between fHRV and neonatal pH or base excess (BE) at birth.We enrolled a prospective pilot cohort of uncomplicated singleton pregnancies at 38-42 weeks' gestation in Milan, Italy, and Liverpool, UK. Fetal monitoring was performed by standard cardiotocography. Simultaneously, with fECG (high sampling frequency) was recorded. To ensure clinician blinding, fECG information was not displayed. Data from the last 60 min preceding onset of second-stage labour were analyzed using clinically validated continuous individualized multiorgan variability analysis (CIMVA) software in 5 min overlapping windows. CIMVA allows simultaneous calculation of 101 fHRV measures across five fHRV signal analysis domains. We validated our mathematical prediction model internally with 80:20 cross-validation split, comparing results to cord pH and BE at birth.The cohort consisted of 60 women with neonatal pH values at birth ranging from 7.44 to 6.99 and BE from -0.3 to -18.7 mmol L(-1). Our model predicted pH from 30 fHRV measures (R(2) = 0.90, P base balance at birth. Further refinement and validation in larger cohorts are needed. These new measurements of fHRV might offer a new opportunity to predict fetal acid-base balance at birth. PMID:25407948

  2. Effect of Al and Ce oxide layers electrodeposited on OC4004 stainless steel on its corrosion characteristics in acid media

    The changes in the corrosion characteristics of stainless steel OC4004 in 0.1 M HNO3 after electrodeposition of thin Al and Ce oxide films on it has been investigated. The Ce2O3-CeO2 layers have been found to possess a pronounced stabilizing effect on the steel passive state and on its corrosion resistance, respectively, whereas the Al2O3 layers do not improve considerably the corrosion behaviour of the SS/Al2O3 system. A twice-lower corrosion current was observed with a ternary SS/Al2O3/Ce2O3-CeO2 system in the passive region, while the zones of potentials, where the steel is in a stable passive state, are not changed. The obtained results permit the assumption that the cerium oxides layer acts as an effective cathode playing a determining role with respect to the improvement of the corrosion behavior of the steel. It has been concluded that when the SS/Al2O3/Ce2O3-CeO2 system is used in media containing nitric acid, the corrosion will proceed at potentials where the passive state of steel would not be disturbed

  3. Electrooxidation of 2-propanol and 2-butanol on the Pt–Ni alloy nanoparticles in acidic media

    Graphical abstract: Schematic representation of 2-propanol electrooxidation on the Pt–Ni alloy. Highlights: ► Electrocatalytic oxidation of 2-propanol and 2-butanol on the Pt–Ni nanoparticles. ► High stability and reproducibility of the Pt–Ni nanoparticles at the CCE. ► Pt–Ni/CCE as a potent electrocatalyst in the oxidation of alcohols in DAFCs. -- Abstract: The platinum–nickel nanoparticles carbon-ceramic modified electrode (Pt–Ni/CCE) was used as a potent electrocatalyst for the electrooxidation of 2-propanol and 2-butanol in a mixture of 0.15 M 2-propanol (or 0.15 M 2-butanol) and 0.1 M H2SO4 solutions. The Pt–Ni/CCE catalyst shows excellent electrocatalytic activity for electrooxidation of these fuels in comparison with platinum nanoparticles of carbon-ceramic modified (Pt/CCE) and smooth Pt electrodes due to the presence of Ni atoms in the alloy which enhances the electrocatalytic activity of Pt toward the oxidation of 2-propanol and 2-butanol and reduces the amount of Pt in the anodic material of direct 2-propanol and 2-butanol fuel cells. Furthermore, the Pt–Ni/CCE catalyst has satisfactory stability and reproducibility for the electrooxidation of 2-propanol and 2-butanol in acidic media when stored in ambient conditions or when used in constant potential applying (chronoamperometry) and continuous potential cycling (cyclic voltammetry) which makes it more attractive for alcohol-based fuel cell applications

  4. Stress corrosion cracking and corrosion fatigue on 316L stainless steel in boric acid concentrated media at 320 C

    Stress Corrosion Cracking (SCC) and Corrosion-Fatigue (CF) tests were performed in autoclave at 320 C in concentrated boric acid chlorinated media in presence of oxygen or hydrogen on type 316L austenitic stainless steel. Crack Growth Rates (CGR) are higher in non deaerated solutions for both SCC and CF than in hydrogenated solutions. CGR are relatively similar in CF and in SCC, excepted for high load ratio in CF where CGR are higher than in SCC. Detailed analysis of the fracture surface shows some distinct features between SCC and CF. Intergranular and transgranular mode of fracture are observed on SCC and CF. Fracture modes depend on the chemistry of solution in SCC and on frequency in CF. Traces of slip bands and crack front marking associated with oxide scale present on fracture surfaces exist in SCC and CF. Fatigue striations appear for low load ratio and high frequency. Secondary intergranular and transgranular cracking is observed only on SCC fracture surfaces and ligament morphology can be different in SCC relative to FC

  5. Preparation of cobalt silicide on graphene as Pt electrocatalyst supports for highly efficient and stable methanol oxidation in acidic media

    Nanostructured CoSi with the diameter of 1-3 nm on graphene have been successfully synthesized by metal organic chemical vapor deposition (MOCVD) of Co(SiCl3)(CO)4 as a precursor supported on graphene. Pt electrocatalysts are then loaded on the CoSi/graphene composites (Pt/CoSi-graphene) using an intermittent microwave heating method. The above materials are characterized by XRD, Raman, TEM, EDS and cyclic voltammograms measurements. The results show that Pt/CoSi-graphene gives 3.2 times higher peak current density than that of commercial Pt/C(TKK) electrocatalyst at the same Pt loadings. In addition, Pt/CoSi-graphene shows superior activity and stability to commercial Pt/graphene for methanol oxidationin in acidic media. The improved catalytic activity and stability is due to the synergistic effect (electron-donating) of CoSi to Pt. Since Pt/CoSi-graphene carries higher catalytic activity and stability comparing with Pt/graphene, less Pt will be required for the same performance and it will in turn reduce the cost of fuel cell electrocatalyst

  6. Correlation Study on Sweetness of Amino Acid with Different Configurations and Quantum Chemical Parameters

    LI Jun-Ling; GU Jun; QIU Guang-Min

    2006-01-01

    Quantum chemical parameters of 10 amino acids with D- and L-configurations were firstly calculated with semi-empirical AM1 method. Furthermore, the relationship between mole- cular structures of D-, L-amino acids and their sweetness were observed. The results show that upon different configurations of amino acids, the sweetness is relative with their formation heat, dipole moment, energy gap of frontier orbital and other parameters. The formation heats of the same amino acids possessing D- and L-configurations are different except glycine. The algebraic value of D- amino acid is generally larger than that of corresponding L-configuration with only one except of tyrosine. The dipole moment of D-amino acid is generally larger than that of corresponding L-amino acid except tyrosine and lysine. The lowest unoccupied orbital energy (ELUMO) of D-amino acid is higher than that of corresponding L-configuration except phenylalanine. △E of D-amino acid is larger than that of L-amino acid except histidine, phenylalanine and lysine. The larger gap will have advantage for its matching with frontier orbital energy of human protein acceptor, which strengthens the interaction between D-amino acid and sweet taste acceptor. Besides, the changing rules of these parameters are generally identical.

  7. Phase angle correlates with n-3 fatty acids and cholesterol in red cells of Nigerian children with sickle cell disease

    Huang Yung-Sheng

    2003-05-01

    Full Text Available Abstract Objective To determine the cholesterol content and fatty acid composition of red cell membrane phospholipids (PL of children with sickle cell disease (SCD and to correlate these levels with whole body phase angle that is related to the integrity and function of cell membranes. Study design Blood samples were obtained from 69 children with SCD and 72 healthy age- and gender-matched controls in Nigeria for the determination of the cholesterol content and proportions of fatty acids in red cell PL. Bioelectrical impedance analysis was used to obtain resistance (R and reactance (Xc from which phase angle was calculated as arctan Xc/R. Cholesterol (normalized to lipid phosphorus and the proportions of individual fatty acids were correlated with phase angle. Results The proportions of palmitic (p Conclusions The fatty acid composition and cholesterol content of tissue membranes in SCD correlate with the phase shift measured by bioelectrical impedance analysis. Phase angle measurements may provide a non-invasive method for monitoring interventions aimed at altering the lipid composition of membranes.

  8. Polyethylene Glycols as Efficient Media for Decarboxylative Nitration of α,β-Unsaturated Aromatic Carboxylic Acids by Ceric Ammonium Nitrate in Acetonitrile Medium: A Kinetic and Mechanistic Study

    K.Ramesh; S. Shylaja; K. C. Rajanna; P. Giridhar Reddy; P. K. Saiprakash

    2013-01-01

    Polyethylene glycols (PEGs) were found to be efficient media for decarboxylative nitration of α,β-unsaturated aromatic carboxylic acids by ceric ammonium nitrate (CAN) in acetonitrile to give β-nitrostyrene derivatives. Kinetics of the reaction exhibited second order kinetics with a first order dependence on [CAN] and [substrate]. Reactions were too sluggish to be studied in the absence of PEG; therefore detailed kinetics were not taken up. Reaction times were reduced from 24 hrs to few hours...

  9. Conversion of carbohydrate biomass to γ-valerolactone by using water-soluble and reusable iridium complexes in acidic aqueous media.

    Deng, Jin; Wang, Yan; Pan, Tao; Xu, Qing; Guo, Qing-Xiang; Fu, Yao

    2013-07-01

    Mild-mannered manipulation: A catalytic method for the conversion of carbohydrate biomass to γ-valerolactone in acidic aqueous media has been developed. The water-soluble iridium complexes were observed to be extremely catalytically active for providing γ-valerolactone in high yields with high TONs. The homogeneous catalysts can also be recycled and reused by applying a simple phase separation process. PMID:23757330

  10. Stabilization of emulsions by gum tragacanth (Astragalus spp.) correlates to the galacturonic acid content and methoxylation degree of the gum

    Ahmadi Gavlighi, Hassan; Meyer, Anne S.; Abang Zaidel, Dayang Norulfairuz;

    2013-01-01

    –270 mg/g), and galactose (∼40–140 mg/g), and also contained fucose, rhamnose, and glucose. The ability of the gums to act as stabilizers in whey protein isolate based emulsions varied. The best emulsion stabilization effect, measured as lowest creaming index ratio after 20 days, was obtained with the A....... fluccosus gum. The emulsion stabilization effect correlated linearly and positively to the methoxylation degree, and galacturonic acid content of the gums, but not to acetyl or fucose content. A particularly high correlation was found between methoxyl level in the soluble gum part and emulsion stabilization...

  11. Serum uric acid levels correlate with recurrence of paroxysmal atrial fibrillation after catheter ablation

    HE Xiao-nan; LI Song-nan; ZHAN Jin-liang; XIE Shuang-lun; ZHANG Zhi-jun; DONG Jian-zeng; YU Rong-hui

    2013-01-01

    Background Recently there has been a great deal of interest in the role of serum uric acid (SUA) in atrial fibrillation (AF).The objective of this study was to establish whether there is a relationship between levels of SUA and recurrence of paroxysmal AF after catheter ablation.Methods Three hundred and thirty patients diagnosed with paroxysmal AF were analyzed.Patients were categorized into quartiles on the basis of their pre-operative SUA measurement and follow-up,and Kaplan-Meier estimation with a Log-rank test was used for the analysis of the influence of SUA on the recurrence of AF.Pre-procedural clinical variables were correlated with the clinical outcome after ablation using multivariate Logistic analysis.A Cox proportional hazards model was used to estimate the relationship between SUA and the recurrence of AF.Results After a mean follow-up of (9.341±3.667) (range 3.0-16.3) months,recurrence rates from the lowest SUA quartile to the highest SUA quartile were 16.0%,26.4%,28.3%,and 29.3% respectively (P=0.014).After adjustment for gender,body mass index (BMI),hypertension,serum levels of high sensitivity C-reactive protein (hsCRP),triglyceride (TG),left atrial diameter (LA),estimated glomerular filtration rate (eGFR),and SUA,there was an increased risk of recurrence in subjects in the highest SUA quartile compared with those in the lowest quartile (hazard ratio 2.804,95% confidence interval 1.466-5.362,P=0.002).Following multivariate Logistical analysis,SUA was found to be an independent predictor of recurrence (hazard ratio 1.613,95% confidence interval 1.601-1.625,P=0.014).Conclusion In a retrospective study of patients with paroxysmal AF undergoing catheter ablation,elevated preoperative SUA levels were associated with a higher rate of recurrence of AF.

  12. Removal of CdTe in acidic media by magnetic ion-exchange resin: A potential recycling methodology for cadmium telluride photovoltaic waste

    Highlights: • Sulfonated magnetic microsphere was prepared as one strong acid cation-exchange resin. • Cd and Te can be removed directly from the highly acidic leaching solution of CdTe. • Good chemical stability, fast adsorbing rate and quick magnetic separation in strong acidic media. • A potential path for recycling CdTe photovoltaic waste. - Abstract: Sulfonated magnetic microspheres (PSt-DVB-SNa MPs) have been successfully prepared as adsorbents via an aqueous suspension polymerization of styrene-divinylbenzene and a sulfonation reaction successively. The resulting adsorbents were confirmed by means of Fourier transform infrared spectra (FT-IR), X-ray diffraction (XRD), transmission electron microscope (TEM), scanning electron microscope equipped with an energy dispersive spectrometer (SEM-EDS) and vibrating sample magnetometer (VSM). The leaching process of CdTe was optimized, and the removal efficiency of Cd and Te from the leaching solution was investigated. The adsorbents could directly remove all cations of Cd and Te from a highly acidic leaching solution of CdTe. The adsorption process for Cd and Te reached equilibrium in a few minutes and this process highly depended on the dosage of adsorbents and the affinity of sulfonate groups with cations. Because of its good adsorption capacity in strong acidic media, high adsorbing rate, and efficient magnetic separation from the solution, PSt-DVB-SNa MPs is expected to be an ideal material for the recycling of CdTe photovoltaic waste

  13. Removal of CdTe in acidic media by magnetic ion-exchange resin: A potential recycling methodology for cadmium telluride photovoltaic waste

    Zhang, Teng, E-mail: zhangteng@mail.iee.ac.cn; Dong, Zebin; Qu, Fei; Ding, Fazhu; Peng, Xingyu; Wang, Hongyan; Gu, Hongwei

    2014-08-30

    Highlights: • Sulfonated magnetic microsphere was prepared as one strong acid cation-exchange resin. • Cd and Te can be removed directly from the highly acidic leaching solution of CdTe. • Good chemical stability, fast adsorbing rate and quick magnetic separation in strong acidic media. • A potential path for recycling CdTe photovoltaic waste. - Abstract: Sulfonated magnetic microspheres (PSt-DVB-SNa MPs) have been successfully prepared as adsorbents via an aqueous suspension polymerization of styrene-divinylbenzene and a sulfonation reaction successively. The resulting adsorbents were confirmed by means of Fourier transform infrared spectra (FT-IR), X-ray diffraction (XRD), transmission electron microscope (TEM), scanning electron microscope equipped with an energy dispersive spectrometer (SEM-EDS) and vibrating sample magnetometer (VSM). The leaching process of CdTe was optimized, and the removal efficiency of Cd and Te from the leaching solution was investigated. The adsorbents could directly remove all cations of Cd and Te from a highly acidic leaching solution of CdTe. The adsorption process for Cd and Te reached equilibrium in a few minutes and this process highly depended on the dosage of adsorbents and the affinity of sulfonate groups with cations. Because of its good adsorption capacity in strong acidic media, high adsorbing rate, and efficient magnetic separation from the solution, PSt-DVB-SNa MPs is expected to be an ideal material for the recycling of CdTe photovoltaic waste.

  14. Monitoring utilizations of amino acids and vitamins in culture media and Chinese hamster ovary cells by liquid chromatography tandem mass spectrometry.

    Qiu, Jinshu; Chan, Pik Kay; Bondarenko, Pavel V

    2016-01-01

    Monitoring amino acids and vitamins is important for understanding human health, food nutrition and the culture of mammalian cells used to produce therapeutic proteins in biotechnology. A method including ion pairing reversed-phase liquid chromatography with tandem mass spectrometry was developed and optimized to quantify 21 amino acids and 9 water-soluble vitamins in Chinese hamster ovary (CHO) cells and culture media. By optimizing the chromatographic separation, scan time, monitoring time window, and sample preparation procedure, and using isotopically labeled (13)C, (15)N and (2)H internal standards, low limits of quantitation (≤0.054 mg/L), good precision (culture media. In a fed-batch process of manufacturing scale bioreactors, two distinguished trends for changes in amino acid concentrations were identified in response to feeding. Ten essential amino acids showed a zigzag pattern with maxima at the feeding days, and 9 non-essential amino acids displayed a smoothly changing profile as they were mainly products of cellular metabolism. Five of 9 vitamins accumulated continuously during the culture period, suggesting that they were fed in access. The method serves as an effective tool for the development and optimization of mammalian cell cultures. PMID:26355770

  15. An Interpretation of the Ancestral Codon from Miller’s Amino Acids and Nucleotide Correlations in Modern Coding Sequences

    Carels, Nicolas; de Leon, Miguel Ponce

    2015-01-01

    Purine bias, which is usually referred to as an “ancestral codon”, is known to result in short-range correlations between nucleotides in coding sequences, and it is common in all species. We demonstrate that RWY is a more appropriate pattern than the classical RNY, and purine bias (Rrr) is the product of a network of nucleotide compensations induced by functional constraints on the physicochemical properties of proteins. Through deductions from universal correlation properties, we also demonstrate that amino acids from Miller’s spark discharge experiment are compatible with functional primeval proteins at the dawn of living cell radiation on earth. These amino acids match the hydropathy and secondary structures of modern proteins. PMID:25922573

  16. Correlation between coronary artery disease severity, left ventricular mass index and carotid intima media thickness, assessed by radio-frequency

    Ciccone Marco M

    2011-11-01

    Full Text Available Abstract Background Intima-media thickness of the common carotid artery (CCA-IMT is a validated marker of systemic atherosclerosis process. The aim of this study was to evaluate the association between coronary artery disease (CAD, left ventricular hypertrophy (LVH and CCA-IMT, assessed by Radio Frequency-Quality Intima Media Thickness (RFQIMT method, the next generation of IMT real-time measurement, based on the direct analysis of the radiofrequency signal and endowed with high accuracy and reproducibility in early detection of arterial wall thickness. Methods 115 patients (76 men, mean age: 65.1 ± 12 years referred to our department and shown significant (≥ 70% luminal obstruction stenosis at least in one major epicardial coronary artery were studied. Coronary angiograms were divided for severity and extent of the disease: 79 patients (69% had one, 24 patients (21% two, 12 patients (10% three major epicardial coronary arteries with ≥ 70% stenosis. All patients underwent echocardiography and carotid ultrasound examination, assessed by RF. Results Dividing RFQIMT data in tertiles, dyslipidaemia (31 patients with IMT ≥ 1.20 mm vs 16 with IMT = 0.91-1.19 vs 25 with IMT ≤ 0.9, p = 0.004, LVMI (153.5 ± 20.6 g/m2 in IMT ≥ 1.20 mm vs 131.2 ± 8.4 g/m2 in IMT = 0.91-1.19 mm vs 114.3 ± 11.1 g/m2 in IMT ≤ 0.9 mm, P 2 = 0.88, RFQIMT remained significantly associated with the dyslipidemia (regression coefficient ± standard error [SE]: 0.057 ± 0.023; p = 0.017, LVMI (regression coefficient ± SE: 0.01 ± 0.001; P Conclusions RFQIMT is a sophisticated method for carotid ultrasound evaluation. Its evaluation in patients with at least one important major epicardial coronary vessel stenosis would help the accuracy in the general assessment of the number of coronary lesions in these patients.

  17. Fatty acid composition in serum correlates with that in the liver and non-alcoholic fatty liver disease activity scores in mice fed a high-fat diet.

    Wang, Xing-He; Li, Chun-Yan; Muhammad, Ishfaq; Zhang, Xiu-Ying

    2016-06-01

    In this study, we investigated the correlation between the serum fatty acid composition and hepatic steatosis, inflammation, hepatocellular ballooning scores, and liver fatty acids composition in mice fed a high-fat diet. Livers were collected for non-alcoholic fatty liver disease score analysis. Fatty acid compositions were analysed by gas chromatography. Correlations were determined by Pearson correlation coefficient. Exposed to a high-fat diet, mice developed fatty liver disease with varying severity without fibrosis. The serum fatty acid variation became more severe with prolonged exposure to a high-fat diet. This variation also correlated significantly with the variation in livers, with the types of fatty acids corresponding to liver steatosis, inflammation, and hepatocellular ballooning scores. Results of this study lead to the following hypothesis: the extent of serum fatty acid variation may be a preliminary biomarker of fatty liver disease caused by high-fat intake. PMID:27179602

  18. Acidity constants in different media (I=0 and I=0.1 M KCl) from the uncertainty perspective.

    Koort, Eve; Gans, Peter; Herodes, Koit; Pihl, Viljar; Leito, Ivo

    2006-07-01

    Procedures for estimating the measurement uncertainty for the acidity constant Ka (or the pKa value) in different media (I=0 and I=0.1 mol L(-1) KCl), as determined by potentiometric titration, are presented. The uncertainty budgets (the relative contributions of the different input quantities to the uncertainty in the result) of the pKa (I=0) and pKa (I=0.1 mol L(-1) KCl) values are compared. Unlike the values themselves, the uncertainties and uncertainty budgets of the values are comparable. The uncertainty estimation procedures are based on mathematical models of pKa measurement and involve the identification and quantification of individual uncertainty sources according to the ISO GUM approach. The mathematical model involves 52 and 48 input parameters for pKa (I=0) and pKa (I=0.1 mol L(-1) KCl), respectively. The relative importance of each source of uncertainty is discussed. In both cases, the main contributors to the uncertainty budget are the uncertainty components due to the hydrogen ion concentration/activity measurement, which provide 63.7% (for pKa (I=0)) and 89.3% (for pKa (I=0.1 mol L(-1) KCl)) of the uncertainty. The remaining uncertainty contributions arise mostly from the limited purity of the acid. From this work, it is clear that the uncertainties of the pKa (I=0.1 mol L(-1) KCl) values tend to be lower than those of the pKa (I=0) values. The main reasons for this are that: (1) the uncertainty due to the residual liquid junction potential is nominally absent in the case of pKa (I=0.1 mol L(-1) KCl) due to the similarly high concentrations of background electrolyte in the calibration solutions and measured solution; (2) the electrode system is more stable in solutions containing the 0.1 mol L(-1) KCl background electrolyte and so the readings obtained in these solutions are more stable. PMID:16791552

  19. Permeability to macromolecular contrast media quantified by dynamic MRI correlates with tumor tissue assays of vascular endothelial growth factor (VEGF)

    Purpose: To correlate dynamic MRI assays of macromolecular endothelial permeability with microscopic area–density measurements of vascular endothelial growth factor (VEGF) in tumors. Methods and material: This study compared tumor xenografts from two different human cancer cell lines, MDA-MB-231 tumors (n = 5), and MDA-MB-435 (n = 8), reported to express respectively higher and lower levels of VEGF. Dynamic MRI was enhanced by a prototype macromolecular contrast medium (MMCM), albumin-(Gd-DTPA)35. Quantitative estimates of tumor microvascular permeability (KPS; μl/min × 100 cm3), obtained using a two-compartment kinetic model, were correlated with immunohistochemical measurements of VEGF in each tumor. Results: Mean KPS was 2.4 times greater in MDA-MB-231 tumors (KPS = 58 ± 30.9 μl/min × 100 cm3) than in MDA-MB-435 tumors (KPS = 24 ± 8.4 μl/min × 100 cm3) (p < 0.05). Correspondingly, the area–density of VEGF in MDA-MB-231 tumors was 2.6 times greater (27.3 ± 2.2%, p < 0.05) than in MDA-MB-435 cancers (10.5 ± 0.5%, p < 0.05). Considering all tumors without regard to cell type, a significant positive correlation (r = 0.67, p < 0.05) was observed between MRI-estimated endothelial permeability and VEGF immunoreactivity. Conclusion: Correlation of MRI assays of endothelial permeability to a MMCM and VEGF immunoreactivity of tumors support the hypothesis that VEGF is a major contributor to increased macromolecular permeability in cancers. When applied clinically, the MMCM-enhanced MRI approach could help to optimize the appropriate application of VEGF-inhibiting therapy on an individual patient basis.

  20. CORRELATION OF CONTENT ASCORBIC ACID IN THE ASSIMILATION APPARATUS BETULA PENDULA ROTH. WITH AGENT BY PATHOLOGICAL

    Михаил Эдуардович Баландайкин

    2014-09-01

    Full Text Available Features of influence of set of anthropogenic factors and phytopathologic state of tree Betula pendula on concentration of ascorbic acid in it assimilation apparatus are considered. By criterion of influence Inonotus obliquus (Pers.: Fr. Pilat and to presence pollution adaptable ability of a plant to action stressful factors, and also possibility of development of the mechanisms which are responsible for inhibition of biosynthesis of ascorbic acid estimated. It is shown that from all analysed in the yielded work abiotic and biotic factors most essentially the pathogenic factor affects change of concentration of ascorbic acid in sheet plates of trees concerning norm.

  1. Correlation between the acid-base properties of the La2O3 catalyst and its methane reactivity.

    Chu, Changqing; Zhao, Yonghui; Li, Shenggang; Sun, Yuhan

    2016-06-28

    Density functional theory and coupled cluster theory calculations were carried out to study the effects of the acid-base properties of the La2O3 catalyst on its catalytic activity in the oxidative coupling of methane (OCM) reaction. The La(3+)-O(2-) pair site for CH4 activation is considered as a Lewis acid-Brönsted base pair. Using the Lewis acidity and the Brönsted basicity in the fluoride affinity and proton affinity scales as quantitative measures of the acid-base properties, the energy barrier for CH4 activation at the pair site can be linearly correlated with these acid-base properties. The pair site consisting of a strong Lewis acid La(3+) site and a strong Brönsted base O(2-) site is the most reactive for CH4 activation. In addition, the basicity of the La2O3 catalyst was traditionally measured by temperature-programmed desorption of CO2, but the CO2 chemisorption energy is better regarded as a combined measure of the acid-base properties of the pair site. A linear relationship of superior quality was found between the energy barrier for CH4 activation and the CO2 chemisorption energy, and the pair site favorable for CO2 chemisorption is also more reactive for CH4 activation, leading to the conflicting role of the "basicity" of the La2O3 catalyst in the OCM reaction. The necessity for very high reaction temperatures in the OCM reaction is rationalized by the requirement for the recovery of the most reactive acid-base pair site, which unfortunately also reacts most readily with the byproduct CO2 to form the very stable CO3(2-) species. PMID:27265027

  2. Phenotypic correlations of fatty acid composition among intramuscular, subcutaneous and intermuscular fat tissues in concentrate-fed beef cattle of differing genotypes

    Aldai Elkoro-Iribe, Noelia; Dugan, M. E. R.; Osoro, K; Z. Wang; Crews, D. H.; C. Li

    2009-01-01

    [EN]In an attempt to predict intramuscular fatty acid composition using easily accessible fat depots, between-tissue correlations were studied in 75 Asturiana de los Valles bulls with different levels of muscular hypertrophy, and 25 Asturiana de la Montan˜ a bulls. Trans-18:1 in intramuscular fat was highly and positively correlated with levels in subcutaneous and intermuscular fats, while levels of total n-3 were not correlated. Predicting intramuscular fatty acid composition using easily ac...

  3. CORRELATION OF CONTENT ASCORBIC ACID IN THE ASSIMILATION APPARATUS BETULA PENDULA ROTH. WITH AGENT BY PATHOLOGICAL

    Михаил Эдуардович Баландайкин

    2014-01-01

    Features of influence of set of anthropogenic factors and phytopathologic state of tree Betula pendula on concentration of ascorbic acid in it assimilation apparatus are considered. By criterion of influence Inonotus obliquus (Pers.: Fr.) Pilat and to presence pollution adaptable ability of a plant to action stressful factors, and also possibility of development of the mechanisms which are responsible for inhibition of biosynthesis of ascorbic acid estimated. It is shown that from all analyse...

  4. The development of a method for the simultaneous measurement of cerium (IV) and chromium (VI) species in nitric acid media - 16124

    The corrosion of stainless steel in nitric acid media is a major concern for the nuclear industry. Several reprocessing schemes such as PUREX (Plutonium Uranium Reduction Extraction) and UREX (Uranium Reduction Extraction) utilise nitric acid media, and an understanding of the behaviour of key chemical species in these process streams is vital if their effect on associated corrosion reactions and their rates is to be accurately assessed and quantified. This will allow for more accurate prediction of the working lifetime of any stainless steel surface in contact with the process stream in question. Two such key species that are found in nuclear process streams are cerium as Ce (IV) and chromium as Cr(VI), both of which may act as corrosion accelerants. The redox chemistry of cerium and chromium in highly active liquor (HAL) will depend on nitrous acid concentration, temperature, acidity, total nitrate and possibly the influence of other dissolved species and hence an analytical technique for the on-line measurement of these quantities would be useful for lifetime prediction and corrosion prevention. As a result of this, a strategy for the simultaneous measurement of both Ce(IV) and Cr(VI) species in the presence of other ions typically found in process streams (such as Iron, Magnesium Neodymium and Aluminium) has been developed. The work presented will discuss the design and implementation of the electrochemical techniques that we have used in the development of this strategy and in the measurement of the species in question. (authors)

  5. Correlation Between Toluene Environmental Monitoring and Biological Index of Urinary Hippuric Acid of Workers in the Coke Industry

    MM Amin

    2007-04-01

    Full Text Available Introduction: Toluene is an organic solvent that it is one of the byproducts in the coke industry. Exposure to toluene causes central nervous system dysfunction and others disorders. Many workers are exposed to toluene due to leakage from tracks. Therefore the aim of this study was to determine the levels of exposure through environmental and biological monitoring of toluene Methods: Air toluene sampling of air inhaled by 36 coke oven workers was done by using activated charcoal tubes and personal sampling pumps. At the end of the shift, urine samples of workers and control group were collected by urine samplers. Air toluene was determined by GC, urinary hippuric acid by HPLC and urine creatinine level was determined by auto analyzer. Results: The mean of air toluene and urinary hippuric acid levels in exposed and control samples were 14.34 ppm, 0.33 and 0.28 g/g creatinine. Air toluene and urinary hippuric acid showed a correlation of r = 0.8. Conclusion: Toluene TWA was lower than the TLV-TWA (p=0.000. Urinary hippuric acid concentration was also lower than the BEI (p=0.008. Difference between exposed and unexposed group was not significant. This study showed that hippuric acid because of its interaction with background factors can not be used as a sensitive biomarker for biomonitoring.

  6. Infrared study of some 2-substituted-6-hydroxy-4-pyrimidine carboxylic acids. Correlation with MO-calculations

    IVAN O. JURANIC

    2000-06-01

    Full Text Available The IR spectra of a series of 2-substituted-6-hydroxy-4-pyrimidine carboxylic acids (substituent = OH, SH, CH3, CH3S and NH2 were studied from the aspect of the influence of the subsitutent on the polarizability of some bonds, keto-enol tautomerism and hydrogen bond formation. The spectra were taken using solids due to the low solubility of the acids. Theoretical calculations were done using the MNDO-AM1 semiempirical molecular-orbital method. The stabilities of various tautomers were calculated simulating the dielectric continuum using the COSMO facility of the MOPAC program package. Theoretical calculations were made for all the possible tautomers of the 2-substituted-6-hydroxy-4-pyrimidine carboxylic acids. For the most stable isomers, the vibrational spectra were calculated. For the majority of the compounds the most stable isomer was identified having the structure 2-Y-6-oxo-4-carboxy-3H-pyrimidine. Besides this structure, for the 2-amino-, and 2-methyl- derivatives the zwitterionic forms have very similar stability. The 2-hydroxy compound is most stable as the 2,6-dioxo-1H, 3H isomer. The calculated vibrations for the compounds with a single stable structure correlate very well with the experimental frequencies. For the 2-methyl- and 2-amino- compounds the correlation is considerably less satisfactory. The most probable reason for this deviation is the existence of two or more tautomets in equilibrium. The correlation of the measured frequencies and the pKa values of the acids, indicate that the same tautomers exist in the solid state and in the solution.

  7. Correlation of common carotid intima media thickness with atherosclerotic cardiovascular events in patients with type 2 diabetes mellitus

    Vascular complications are a major cause of morbidity and mortality in patients with diabetes mellitus and affect the quality of life. Atherosclerosis, which is the major underlying risk factor, is accelerated in diabetes. To reduce morbidity and mortality, identification of patients with a high risk for development of vascular events is necessary. Apart from other risk prediction models, detection of subclinical atherosclerosis at common carotid site by B-mode ultrasonography which is a noninvasive and reliable method, can add to the benefit and improve risk prediction. Population based studies have revealed that increased Common Carotid Intima Media Thickness (CCIMT) is associated with prevalent coronary artery disease and is a surrogate marker of cardiovascular events. Aim was to evaluate whether increased CCIMT is associated with increased risk of cardiovascular events in patients with type 2 diabetes. A total of 90 patients with type 2 diabetes who were included in the study, were divided in two groups. Group 1: without vascular events and group 2: with vascular events. Apart from patient's demographics, detailed history of events physical examination, through blood analysis for fasting, post postprandial blood sugar, serum cholesterol, TG, renal function test glycosylated Hb, chest x-ray, ECG were recoded. CCIMT was measured by B-mode ultrasonography using high frequency linear transducer, by a specialist radiologist (blind to all clinical and laboratory findings) by standard protocol as described in literature. Mean of the three readings in each side were used for statistical analysis. Our results showed that of the 90 patients studied, 45 diabetes mellitus (DM) patients had atherosclerotic events and significantly higher CCIMT value (mean value of 1.005 +- 0.17 mm) whereas as 45 comparable DM patients without sclerotic events and lower CCIMT values (0.798 +- 0.12 mm) (p0.99 mm) had a statistically significant association with high odds ratios for

  8. Correlation between zoledronic acid infusion and repeat vertebroplasty surgery in osteoporotic patients.

    Lin, Tung-Yi; Yang, Shih-Chieh; Tsai, Tsung-Ting; Lai, Po-Liang; Fu, Tsai-Sheng; Niu, Chi-Chien; Chen, Lih-Huei; Chen, Wen-Jer

    2016-05-01

    Objective The incidence of bone fractures rapidly increases as people age, mostly due to bone loss resulting from osteoporosis. The purpose of this study is to compare the rates of repeat vertebroplasty in osteoporotic patients treated with or without zoledronic acid (ZOL) infusion following initial vertebroplasty. Research design and methods We conducted a retrospective chart review of osteoporotic patients who underwent vertebroplasty from June 2009 to June 2012. Patients with existing vertebral fracture(s) were retrospectively divided into two groups according to whether or not they received zoledronic acid infusion after initial vertebroplasty. Zoledronic acid infusion was intravenously administered once a year for three consecutive years, as a single 5 mg dose in 100 mL solution infused over at least 15 minutes. The primary efficacy variable was the number of patients requiring repeat vertebroplasty procedures after the initial surgery due to subsequent vertebral fractures. The Cox proportional hazards model was used to compare the risk ratios of repeat vertebroplasty between these two groups. Results A total of 1646 patients, including 456 males and 1190 females (age range: 65-89 years), were enrolled. Compared to the 1595 patients who did not receive osteoporosis medication, the 51 patients treated with zoledronic acid infusion demonstrated a significantly lower rate of repeat vertebroplasty. In the ZOL-treated group, only 4% of the patients (2/51) required a second vertebroplasty, compared to 13% (206/1595) in the non-ZOL-treated group (p = 0.032). Conclusions The results indicate that osteoporotic patients who undergo vertebroplasty are significantly less likely to require reoperation if treated with zoledronic acid infusion. However, since the number of male patients in the ZOL-treated group was limited, and since Taiwan's National Health System program does not cover the cost of receiving zoledronic acid infusions for male patients, the

  9. Yeasts isolation for bio-reduction of wines volatile acidity: Combined use of differential and selective culture media

    Vilela, Alice; Amaral, Carla; Schuller, Dorit; Mendes-Faia, Arlete; Côrte-Real, Manuela

    2016-01-01

    The main component of the volatile acidity of wines is acetic acid. The maximum acceptable limit for volatile acidity in most wines is 1.2 g/L of acetic acid due to the associated unpleasant vinegar aroma and acrid taste. Acetic acid is a by-product of alcoholic fermentation by Saccharomyces cerevisiae under winemaking conditions. However, this acid may also appear in wine due to spoilage agents, such as the acetic acid bacteria and spoilage yeasts. Winemakers have been using a refermentation...

  10. Studies on Tinospora cordifolia monosugars and correlation analysis of uronic acids by spectrophotometric methods and GLC.

    Kumar, Vineet; Nagar, Shipra

    2014-01-01

    Cold water-soluble (CWSP) and hot water soluble polysaccharides (HWSP) from Tinospora cordifolia stems were isolated and purified in 2.99% and 1.99% yield respectively. Complete hydrolysis followed by paper chromatography and GLC analysis indicated the presence of L-rhamnose, L-arabinose, D-xylose, D-mannose, D-galactose and D-glucose in molar ratio of 0.857, 1.106, 0.727, 0.526, 0.708 and 95.763 in CWSP and 0.697, 0.777, 2.048, 0.777, 0.292 and 95.408 in HWSP. The uronic acid content in the polysaccharide has been studied extensively using assorted approaches. It was quantitatively estimated by GLC analysis and spectrophotometric methods using carbazole, m-hydroxydiphenyl and 3,5-dimethylphenol as colorimetric reagents. GLC analyses indicated galacturonic acid content of 3.06% and 5.16% in CWSP and HWSP respectively. Estimation of uronic acid using 3,5-dimethylphenol corroborated the above analysis. The study resulted in composition of constituent monosugars of CWSP and HWSP and co-relation analysis of uronic acid content, leading to an unambiguous structural analysis. PMID:24274509

  11. Maternal fatty acid desaturase genotype correlates with infant immune responses at 6 months

    Muc, Magdalena; Kreiner-Møller, Eskil; Larsen, Jeppe Madura;

    2015-01-01

    Breast milk long-chain PUFA (LCPUFA) have been associated with changes in early life immune responses and may modulate T-cell function in infancy. We studied the effect of maternal fatty acid desaturase (FADS) genotype and breast milk LCPUFA levels on infants' blood T-cell profiles and ex vivo-pr...

  12. Electrodeposited gold nanoparticles on glassy carbon: Correlation between nanoparticles characteristics and oxygen reduction kinetics in neutral media

    Gold nanoparticles (AuNPs) were deposited onto glassy carbon (GC) by constant potential electrolysis (CPE) using various sets of potential and duration from −0.3 to 0.7 V/SHE and 10 to 1800 s, respectively. The physico-chemical characteristics of the as-obtained deposits were investigated by cyclic voltammetry (CV) in H2SO4, field emission gun scanning electron microscopy (FEG-SEM), and Pb underpotential deposition (UPD). Their performances toward the oxygen reduction reaction (ORR) in a NaCl–NaHCO3 (0.15 M/0.028 M, pH 7.4) neutral solution were examined and correlated to AuNPs size and density. The best results were obtained using the deposits which exhibited a high density (555 ± 49 μm−2) of relatively small AuNPs (25 ± 12 nm). The Koutecky–Levich treatment was systematically applied to all the deposits in order to determine the number of electrons n exchanged for the ORR in the potential range from 0.1 to −1.0 V/SHE. The values of the cathodic transfer coefficients βn were also extracted and compared to the values reported for unmodified GC and bulk Au. A map of the βn values as a function of AuNPs electrodeposition potential and duration was also provided

  13. Correlation of Erythrocyte Trans Fatty Acids with Ovulatory Disorder Infertility in Polycystic Ovarian Syndrome

    Aisa Ghaffarzad

    2014-07-01

    Full Text Available Trans fatty acids are considered to be the important modifiable factor of the ovulatory infertility disorder. The purpose of this study was to test the hypothesis that higher trans fatty acids of erythrocytes (RBC are associated with the risk of ovulatory infertility disorder in polycystic ovarian syndrome (PCOS.Thirty five infertile women with polycystic ovarian syndrome, defined by AES criteria and 29 age-matched healthy women as a control group were recruited for the study. After physical measurements and nutritional assessment, blood samples were collected. Fasting serum glucose and insulin were measured, and then insulin resistance was calculated by homeostasis model assessment (HOMA-IR. Erythrocyte fatty acids were measured by gas chromatography.The patients group had higher waist circumference (WC, insulin levels, HOMA-IR than controls (p< 0.05. Also, case group had lower percentage of normal BMI (BMI<25, physical activity and education levels than healthy women (p< 0.05. Among RBC trans fatty acids only trans linoleate (18:2t were significantly higher in case group than control women (p= 0.019. PCOS group tended to consume more food rich in TFAs than the control group. Logistic regression analysis also showed that only 18:2t is positively associated with risk of ovulatory disorder infertility in PCOS (OR= 1.225, 95% CI. 1.024-1.465; P= 0.026, which was not affected after adjustment for BMI, physical activity and education levels.The results suggested that RBC trans fatty acids might be a predictor of increased risk for ovulatory infertility disorder in women with PCOS.

  14. STUDY OF CAROTID INTIMA MEDIA THICKNESS IN PATIENTS WITH ACUTE ISCHEMIC STROKE AND ITS CORRELATION WITH RISK FACTORS OF ISCHEMIC STROKE - A CASE CONTROL STUDY

    Rajeev

    2013-10-01

    Full Text Available ABSTRACT: Stroke is the leading cause of mortality worldwide. Carotid Intima Media Thickness (CIMT is a marker of atherosclerosis and is also a marker for ischemic stroke. AIMS: 1 To assess the value of carotid intima media thickness at which patients with risk factors can develop acute ischemic stroke. 2 To correlate carotid intima media thickness with risk factors of acute ischemic stroke. MATERIAL & METHODS: This study was done at KIMS Hospital, Bangalore between December 2010 to September 2012. This is a case control observational study which has a sample size of 50 cases and 50 controls. Method of collection of data was by patient evaluation which was done by taking detailed history, clinical examination and laboratory investigations throu gh a proforma specially designed for this study. Cases were subjects who had ischemic stoke and Infarct proven by CT/MRI of brain, Controls were subjects without stroke matched to cases by age, gender and risk factors like diabetes, hypertension, smoking a nd dyslipidemia. S ubjects in both groups underwent carotid Doppler investigation with 7.5 Mhz linear superficial array probe to determine CIMT and presence of plaques. RESULTS: Out of 50 cases, 46 had CIMT between 0.06 - 0.20 cm [92%] and out of 50 controls, 45 had CIMT between 0.06 - 0.20 cm[90%]. Most of our cases had CIMT above 0.06 cm, so we can hypothesize that people with risk factors having CIMT above 0.06 cm are more prone for ischemic cerebro vascular accidents. Mean CIMT in cases with risk factors is significantly increased when compared to controls with risk factors. CONCLUSION: People with risk factors [ age > 50 years, DM , HTN , Smoking and Dyslipidemia] having CIMT above 0.06 cm are more prone for ischemic CVA, so people with risk factors should u ndergo screening for CIMT measurement by Carotid Doppler which is non invasive and cost effective and if their CIMT is above 0.06 cm they should undergo early medical intervention to take care

  15. Common Carotid Intima Media Thickness and Ankle-Brachial Pressure Index Correlate with Local but Not Global Atheroma Burden: A Cross Sectional Study Using Whole Body Magnetic Resonance Angiography

    Weir-McCall, Jonathan R.; Khan, Faisel; Lambert, Matthew A.; Carly L Adamson; Gardner, Michael; Gandy, Stephen J.; Ramkumar, Prasad Guntur; Belch, Jill J. F.; Struthers, Allan D.; Rauchhaus, Petra; Andrew D Morris; Houston, J. Graeme

    2014-01-01

    Background Common carotid intima media thickness (CIMT) and ankle brachial pressure index (ABPI) are used as surrogate marker of atherosclerosis, and have been shown to correlate with arterial stiffness, however their correlation with global atherosclerotic burden has not been previously assessed. We compare CIMT and ABPI with atheroma burden as measured by whole body magnetic resonance angiography (WB-MRA). Methods 50 patients with symptomatic peripheral arterial disease were recruited. CIMT...

  16. Common carotid intima media thickness and ankle-brachial pressure index correlate with local but not global atheroma burden:A cross sectional study using whole body magnetic resonance angiography

    Weir-McCall, Jonathan R.; Khan, Faisel; Lambert, Matthew A.; Carly L Adamson; Gardner, Michael; Gandy, Stephen J.; Ramkumar, Prasad Guntur; Belch, Jill J. F.; Struthers, Allan D.; Rauchhaus, Petra; Andrew D Morris; Houston, J. Graeme

    2014-01-01

    Background: Common carotid intima media thickness (CIMT) and ankle brachial pressure index (ABPI) are used as surrogate marker of atherosclerosis, and have been shown to correlate with arterial stiffness, however their correlation with global atherosclerotic burden has not been previously assessed. We compare CIMT and ABPI with atheroma burden as measured by whole body magnetic resonance angiography (WB-MRA). Methods: 50 patients with symptomatic peripheral arterial disease were recruited. CI...

  17. Individual variability in verbal fluency correlates with γ-aminobutyric acid concentration in the left inferior frontal gyrus.

    Nakai, Tomoya; Okanoya, Kazuo

    2016-09-01

    A particular feature of the inferior frontal gyrus (IFG), which is considered a central region for language processing, is leftward functional/anatomical asymmetry. However, previous studies have not clearly shown lateralization of neurotransmitters in the cortical regions. Using proton magnetic resonance spectroscopy, we measured γ-aminobutyric acid (GABA) concentrations in the bilateral IFG. To evaluate individual variability in linguistic performance, we further used a verbal fluency test. Although GABA+/creatine (Cr) values were not different between the left and the right IFG, we found a significant correlation between category fluency scores and GABA+/Cr values in the left IFG. No correlation was found between letter fluency scores and GABA+/Cr values. We also confirmed that the result was independent of the references used (Cr and H2O). Our results show a new physiological basis of linguistic performance as well as leftward asymmetry of the IFG. PMID:27454241

  18. Expression of a functional jasmonic acid carboxyl methyltransferase is negatively correlated with strawberry fruit development.

    Preuß, Anja; Augustin, Christiane; Figueroa, Carlos R; Hoffmann, Thomas; Valpuesta, Victoriano; Sevilla, José F; Schwab, Wilfried

    2014-09-15

    The volatile metabolite methyl jasmonate (MeJA) plays an important role in intra- and interplant communication and is involved in diverse biological processes. In this study, we report the cloning and functional characterization of a S-adenosyl-l-methionine:jasmonic acid carboxyl methyltransferase (JMT) from Fragaria vesca and Fragaria×ananassa. Biochemical assays and comprehensive transcript analyses showed that JMT has been erroneously annotated as gene fusion with a carboxyl methyltransferase (CMT) (gene15184) in the first published genome sequence of F. vesca. Recombinant FvJMT catalyzed the formation of MeJA with KM value of 22.3μM while FvCMT and the fusion protein were almost inactive. Activity of JMT with benzoic acid and salicylic acid as substrates was less than 1.5% of that with JA. Leucine at position 245, an amino acid missing in other JMT sequences is essential for activity of FvJMT. In accordance with MeJA levels, JMT transcript levels decreased steadily during strawberry fruit ripening, as did the expression levels of JA biosynthesis and regulatory genes. It appears that CMT has originated by a recent duplication of JMT and lost its enzymatic activity toward JA. In the newest version of the strawberry genome sequence (June 2014) CMT and JMT are annotated as separate genes in accordance with differential temporal and spatial expression patterns of both genes in Fragaria sp. In conclusion, MeJA, the inactive derivative of JA, is probably involved in early steps of fruit development by modulating the levels of the active plant hormone JA. PMID:25046752

  19. Measurement and correlation of phase equilibrium data of the mixtures consisting of butyric acid, water, cyclohexanone at different temperatures

    Highlights: ► Liquid phase equilibria of (water + BA + cyclohexanone) system were investigated. ► Experimental LLE data were correlated with NRTL and UNIQUAC models. ► Distribution coefficients and separation factors were evaluated. - Abstract: In this work, experimental solubility and tie-line data for the (water + butyric acid + cyclohexanone) system were obtained at T = (298.2, 308.2, and 318.2) K and atmospheric pressure. The ternary system investigated exhibits type-1 behavior of LLE. The experimental tie-line data were compared with those correlated by the UNIQUAC and NRTL models. The consistency of the experimental tie-line data was determined through the Othmer Tobias and Hand correlation equations. Distribution coefficients and separation factors were evaluated over the immiscibility regions. A comparison of the extracting capability of the solvent at different temperatures was made with respect to separation factors. The Katritzky and Kamlet–Abboud–Taft multiparameter scales were applied to correlate distribution coefficients and separation factors in this ternary system. The LSER models values were interpreted in terms of intermolecular interactions.

  20. Effects of caffeic acid phenethyl ester and erdosteine on radiocontrast media-induced oxidative stress and histopathological changes in rat testicular tissue

    Yılmaz, H. Ramazan; Uz, Efkan; Yeşildağ, Ahmet; Özden, Ahmet; Sırmalı, Rana; Agackiran, Yetkin; Vural, Hüseyin

    2013-01-01

    The aim of this study was to determine the possible protective role of caffeic acid phenethyl ester (CAPE) and erdosteine on testicular toxicity of radiocontrast media (RCM) in rats. A total of thirty-five male Wistar albino rats were included in this study. All animals were equally and randomly divided into four groups as follows: Controls (n=10), RCM-treated (n=8), RCM + erdosteine-treated (n=7) and RCM + CAPE-treated (n=10) groups. RCM was intraperitoneally (i.p.) administered ...

  1. Detection of hyaluronidase activity using fluorescein labeled hyaluronic acid and fluorescence correlation spectroscopy

    Rich, Ryan M.; Mummert, Mark; Foldes-Papp, Zeno; Gryczynski, Zygmunt; Borejdo, Julian; Gryczynski, Ignacy; Fudala, Rafal

    2012-01-01

    The over-expression of hyaluronidase has been observed in many types of cancer, suggesting that it may have utility for diagnosis. Here we present a technique for the detection of hyaluronidase using Fluorescence Correlation Spectroscopy (FCS). Hyaluronan macromolecules (HAs) have been heavily labeled with fluorescein amine resulting in strong self-quenching. In the presence of hyaluronidase, HA is cleaved into smaller, fluorescein-labeled fragments and the self-quenching is released. Such cl...

  2. Chronic silent otitis media.

    Paparella, Michael M; Schachern, Patricia A; Cureoglu, Sebahattin

    2002-01-01

    Otitis media occurs along a continuum. For example, otitis media with effusion characterized by fluid pathology can lead to chronic otitis media plus chronic mastoiditis, characterized by the presence of intractable tissue pathology such as cholesteatoma, cholesterol granuloma or granulation tissue. The literature defines chronic otitis media as having a tympanic membrane perforation and otorrhea. Amongst many other sequelae, which can result from the continuum, an important common one is chronic silent otitis media. This overlooked entity which includes pathology beneath an intact tympanic membrane is commonly seen in our human temporal bone laboratory and in patients. The clinical pathological correlates of this important disease are discussed herein. PMID:12021496

  3. Oriented Fiber Filter Media

    R. Bharadwaj

    2008-06-01

    Full Text Available Coalescing filters are widely used throughout industry and improved performance will reduce droplet emissions and operating costs. Experimental observations show orientation of micro fibers in filter media effect the permeability and the separation efficiency of the filter media. In this work two methods are used to align the fibers to alter the filter structure. The results show that axially aligned fiber media improve quality factor on the order of 20% and cutting media on an angle from a thick layered media can improve performance by about 40%. The results also show the improved performance is not monotonically correlated to the average fiber angle of the medium.

  4. Third phase formation in the extraction of Th(NO3)4 by tri-2-methyl butyl phosphate from nitric acid media

    Third phase formation in the extraction of Th(IV) by tri-2-methyl butyl phosphate (T2MBP) in various diluents such as n-dodecane, n-tetradecane and n-hexadecane from nitric acid media has been investigated for the first time. The limiting organic concentration (LOC) and maximum organic concentration (MOC) as well as critical aqueous concentration (CAC) and saturated aqueous concentration (SAC) were measured as a function of equilibrium aqueous acidity. Data on LOC and MOC values have been generated with various concentrations of T2MBP (1.1 M, 1.38 M and 1.65 M) in n-dodecane at 303 K. LOC and CAC values have been measured for the extraction of Th(IV) by 1.1 M T2MBP/n-hexadecane at various temperatures (298 K, 303 K and 313 K) as a function of equilibrium aqueous acidity. Effect of temperature on third phase formation has been studied in the extraction of Th(IV) from its solution with near zero free acidity by 1.1 M T2MBP in n-tetradecane and n-hexadecane as diluents. Data on extraction of nitric acid in the absence and presence of Th(IV) by T2MBP/n-dodecane is also reported in this paper. (orig.)

  5. A study on the alkalimetric titration with gran plot in noncomplexing media for the determination of free acid in spent fuel solutions

    Based on the study of hydrolysis behaviour of U(VI) ion and major fission product metal ions such as Cs(I), Ce(III), Nd(III), Mo(VI), Ru(II), and Zr(VI) in the titration media, the performance of noncomplexing-alkalimetric titration method for the determination of free acid in the presence of these metal ions was investigated and its results were compared to those from the complexing methods. The free acidities could be determined as low as 0.05 meq in uranium solutions in which the molar ratio of U(VI)/H+ was less than 5, when the end-point of titration was estimated by Gran plot. The biases in the determinations were less than ±1% and about +3% respectively for 0.4 meq and 0.05 meq of free acid at the U(VI)/H+ molar ratio of up to 5. Applicability of this method to the determination of free acid in spent fuel solutions was confirmed by the analysis of nitric acid content in simulated spent fuel solutions and in a real spent fuel solution

  6. Correlation between 24-h urine protein, spot urine protein/creatinine ratio, and serum uric acid and their association with fetomaternal outcomes in preeclamptic women

    Nischintha, S.; P Pallavee; Ghose, Seetesh

    2014-01-01

    Background: It is well-known that estimation of 24-h urine protein and spot urine protein/creatinine (P/C) ratio are commonly performed investigations to assess proteinuria in preeclamptic women. Serum uric acid has been shown to correlate well with disease severity in preeclampsia. Materials and Methods: A total of 24-h urine protein estimation, spot urine P/C ratio, and serum uric acid measurements were carried out in 75 pregnant preeclamptic women and the correlation between these investig...

  7. The synthesis of astaxanthin esters,independent of the formation of cysts,highly correlates with the synthesis of fatty acids in Haematococcus pluvialis

    2008-01-01

    The compositions and contents of astaxanthin esters and fatty acids in four types of Haematococcus pluvialis cells were studied by HPLC and GC-MS. Results showed that the synthesis and accumulation of astaxanthin was independent of the formation of cysts, but was highly correlated with the synthesis and accumulation of fatty acids, though it is an well known phenomenon that the accumulation of astaxanthin is usually accompanied by the formation of cyst. The red cysts contain more than 30% of fatty acids, with 81% of the unsaturated fatty acids. Taken together, besides a resource of astaxanthin, H. pluvialis would be a good resource of valuable fatty acids.

  8. Correlation analysis between the carotid artery ather osclerosis severity of patients with lacunar infarct and the level of serum uric acid, high-sensitivity C-reactive protein

    WANG Shu

    2013-01-01

    Full Text Available Background Nowadays, clinical practice shows that the number of patients with cerebral infarction increases year by year in young and middle-aged adults with unclear causes. This paper aims to investigate the correlation between the level of serum uric acid (UA, high-sensitivity C-reactive protein (hsCRP and the degree of carotid atherosclerosis by detecting the level of UA, hsCRP and carotid intima-media thickness (IMT in young and middle-aged patients with lacunar infarct. Methods By using Holland Philips HT-11 color Doppler ultrasonic diagnostic apparatus with linear type probe and 7.50MHz frequency, IMT of end-diastolic distal and bifurcation of arteria carotis communis and proximal internal carotid artery were measured respectively on 186 patients with definitely diagnosed lacunar infarct. As a result, average values were taken as the IMT values. IMT < 1.00 mm was regarded as negative result and 1.00 mm ≤IMT < 1.20 mm was thickening of carotid artery intima. Carotid artery plaque formation was regarded with echo structure existing in the lumen or abnormal blood flow deficits into the lumen, or local IMT ≥1.20 mm at vertical and horizontal scan. At the same time, the levels of UA and hsCRP were detected, and correlation analysis was made between them and IMT. Results The values of UA, hsCRP and IMT in the case group were higher than that in the control group (P = 0.000. The differences among the case subgroups including IMT thickening group, plaque formation group and IMT normal group were statistically significant (P < 0.01, for all. There was linear correlation between the levels of UA, hsCRP and IMT ( r = 0.923, P = 0.000; r = 0.955, P = 0.008. Conclusion UA and hsCRP involve in the formation of atherosclerosis plaque and play an important role in the first-onset lacunar infarct patients without hypertension and other risk factors.

  9. Novel method for determination of uranium isotopes in environmental samples by liquid-liquid extraction with triisooctylamine in sulfuric and hydrochloric acid media

    Novel and robust method for determination of uranium isotopes in various environmental materials is presented. The method is based on total decomposition of the solid materials by the use of closed vessels microwave acid digestion systems and pre concentration of uranium from the liquid samples. The separation of uranium from interfering radionuclides and stable matrix elements is attained by liquid-liquid extraction with triisooctylamine/xylene in sulfuric and consecutively in hydrochloric acid media. Purified uranium is electrodeposited on a stainless steel disks and then measured by alpha spectrometry. The critical steps in the method were examined. The analytical method has been successfully applied to the determination of uranium isotopes in mineral and tap waters, as well as in soils from Northwestern Bulgaria. The analytical quality was checked by analyzing reference materials with different matrices. (author)

  10. Selective extraction of palladium with caffeine from acidic chloride media; Sansei enkabutsu yoeki karano kafuein ni yoru parajiumu no sentakuteki chushutsu

    Kaikake, K.; Baba, Y. [Miyazaki University, Miyazaki (Japan). Faculty of Engineering

    1999-06-10

    In order to examine the possibility of caffeine as an extractant, the extraction of metal ions from acidic chloride media was studied at 298 K using the mixture solvent of chloroform and 2-ethyl-1-hexanol. Caffeine has exhibited a high selectivity for palladium (2) over base metals such as copper (2), nickel (2), and iron (3), and over precious metal such as platinum (4). The stoichiometric relation in the extraction of palladium (2) with caffeine was elucidated by examining the effects of chloride ion, hydrogen ion, and caffeine concentrations on its extractability. In addition, palladium (2) was found to be extracted selectively with caffeine from the mixture containing a 25-fold amount of platinum (4) or copper (2). The stripping of palladium (2) was performed to an extent of 80% by a single batchwise treatment with an aqueous mixture solution of hydrochloric acid and thiourea. (author)

  11. 1H-1H correlations across N-H···N hydrogen bonds in nucleic acids

    In 2HJNN-COSY experiments, which correlate protons with donor/acceptor nitrogens across Nd···HNa bonds, the receptor nitrogen needs to be assigned in order to unambiguously identify the hydrogen bond. For many situations this is a non-trivial task which is further complicated by poor dispersion of (Na,Nd) resonances. To address these problems, we present pulse sequences to obtain direct, internucleotide correlations between protons in uniformly 13C/15N labeled nucleic acids containing Nd···HNa hydrogen bonds. Specifically, the pulse sequence H2(N1N3)H3 correlates H2(A,ω1):H3(U,ω2) protons across Watson-Crick A-U and mismatched G·A base pairs, the sequences H5(N3N1)H1/H6(N3N1)H1 correlate H5(C,ω1)/H6(C,ω1):H1(G,ω2) protons across Watson-Crick G-C base pairs, and the H2(N2N7)H8 sequence correlates NH2(G,A,C;ω1):H8(G,A;ω2) protons across G·G, A·A, sheared G·A and other mismatch pairs. These 1H-1H connectivities circumvent the need for independent assignment of the donor/acceptor nitrogen and related degeneracy issues associated with poorly dispersed nitrogen resonances. The methodology is demonstrated on uniformly 13C/15N labeled samples of (a) an RNA regulatory element involving the HIV-1 TAR RNA fragment, (b) a multi-stranded DNA architecture involving a G·(C-A) triad-containing G-quadruplex and (c) a peptide-RNA complex involving an evolved peptide bound to the HIV-1 Rev response element (RRE) RNA fragment

  12. Correlations Between Serum Uric Acid Level and Disease Activity, Intrathecal Inflammation Reactivity in Patients with Multiple Sclerosis

    Cai-yan Liu; Yan Xu; Li-ying Cui; Bin Peng; Li-zhen Zhong; Xing-wang Chen; Jian-ming Wang

    2012-01-01

    Objective To explore the correlations between serum uric acid (UA) levels and the clinical and cerebrospinal fluid (CSF) parameters of multiple sclerosis (MS).Methods The medical reports of 47 MS patients admitted to Peking Union Medical College Hospital during 2008 and 2010 were reviewed.And 49 age- and gender-matched cerebral infarction patients were enrolled as control.The mean serum UA level of the MS patients was compared with that of the control group.The correlations betveen the UA levels and the clinical parameters including gender,disease duration,relapse rate,and disease disabilities as assessed by the Expanded Disability Status Scale score,were explored.Forty-one patients had CSF examinations.The correlations between the UA levels and the CSF parameters reflecting inflammation and tissue damage,including CSF protein,white blood cell count,oligoclonal band,24-hour IgG index,and myelin basic protein,were also investigated.Results The mean serum UA level in the MS patients was lower than that in the control group (247.75 ± 52.59 μmol/L vs.277.94 ± 74.33 μmol/L,P=0.025) and inversely correlated with the relapse rate (P=0.049).MS patients with lower serum UA levels tended to have higher white blood cell counts and myelin basic protein level.But there was no correlation between CSF protein levels (r=0.165,P=0.273),white blood cell counts (r=0.051,P=0.732),IgG index (r =0.045,P=0.802),or myelin basic protein level (r =0.248,P=0.145) and the serum UA level,respectively.Conclusion In MS patients,UA levels might partly reflect the extent of disability and inflammation.

  13. Sensory Description of Cultivars (Coffea Arabica L. Resistant to Rust and Its Correlation with Caffeine, Trigonelline, and Chlorogenic Acid Compounds

    Larissa de Oliveira Fassio

    2016-01-01

    Full Text Available Considering the importance of the chemical compounds in Arabica coffee beans in the definition of the drink sensory quality and authentication of coffee regions, the aim of this study was to evaluate, from principal component analysis—PCA—if there is a relation between the caffeine, trigonelline, and chlorogenic acid (5-CQA content and the sensory attributes of the drink, and in this context, enabling the differentiation of cultivars in two coffee-producing regions of Brazil. We evaluated seven rust-resistant Coffea arabica cultivars, and two rust-susceptible cultivars in two cultivation environments: Lavras, in the southern region of Minas Gerais state, and Patrocinio in the Cerrado region of Minas Gerais. The flavor and acidity were determinant for differentiation of the cultivars and their interaction with the evaluated environments. Cultivars Araponga MG1, Catigua MG2, and Catigua MG1 are the most suitable for the production of specialty coffee in the state of Minas Gerais. A poor correlation was found between caffeine, trigonelline, 5-CQA contents, and fragrance, flavor, acidity, body, and final score attributes. However, these compounds enabled the differentiation of the environments. The PCA indicated superiority in the sensory quality of cultivars resistant to rust, compared to the control, Bourbon Amarelo, and Topázio MG1190.

  14. Serum liver fatty acid binding protein levels correlate positively with obesity and insulin resistance in Chinese young adults.

    Juan Shi

    Full Text Available BACKGROUND: Liver fatty acid-binding protein (FABP1 plays an inconclusive role in adiposity. We investigated the association of serum FABP1 levels with obesity and insulin resistance in Chinese young people under 30 years old. METHODOLOGY AND PRINCIPAL FINDINGS: Cross-sectional analysis including 200 obese and 172 normal-weight subjects matched for age and sex, anthropometric measurements were performed and serum FABP1 and biochemical characteristics were measured. Insulin resistance was determined by homeostasis model assessment of insulin resistance (HOMA-IR and by the insulin sensitivity index (S(i derived from Bergman's minimal model. FABP1 levels in obese subjects were significantly higher than those in normal-weight subjects (p<0.001 and the significance remained after adjustment for age, gender, alanine and aspartate aminotransferases (p<0.001. Serum FABP1 levels were significantly correlated with many metabolic-related parameters, with BMI and triglycerides as the independent determinants. FABP1 levels remained an independent risk factor of insulin resistance assessed by binary S(i (OR = 1.868 per SD unit, 95% CI [1.035-3.373], p = 0.038 after adjustment for age, sex, BMI, waist circumference, systolic blood pressure, serum triacylglycerol, total cholesterol, HDL- and LDL-cholesterol,. FABP1 levels were also elevated with an increasing number of components of the metabolic syndrome (p for trend <0.001. Multiple regression modeling for the MetS and its components demonstrated that hypertriglyceridemia and low HDL-cholesterol were significantly correlated to serum FABP1 levels. CONCLUSIONS AND SIGNIFICANCE: Serum FABP1 correlates positively with obesity and insulin resistance in Chinese young adults. Our data supports the fact that FABP1 might be an important mediator participating in fatty acid metabolism and energy balance.

  15. High acceleration of the direct aldol reaction cocatalyzed by BINAM-prolinamides and benzoic acid in aqueous media

    Guillena Townley, Gabriela; Hita López, María del Carmen; Nájera Domingo, Carmen

    2006-01-01

    The enantioselective direct aldol reaction, organocatalyzed by recoverable BINAM-prolinamide derivatives can be highly accelerated by a catalytic amount of a carboxylic acid without a detrimental of the obtained enantioselectivities. From the study of suitable acids and reaction conditions, benzoic acid in aqueous DMF or in water was shown to give the best results with high yields and enantioselectivities. Thus, the reaction between p-nitrobenzaldehyde and acetone catalyzed by (Sa)-B...

  16. Dissolution Profile of Mefenamic Acid Solid Dosage Forms in Two Compendial and Biorelevant (FaSSIF) Media

    Nurhikmah, Wilda; Sumirtapura, Yeyet Cahyati; Pamudji, Jessie Sofia

    2016-01-01

    Mefenamic acid is a non-steroidal anti-inflammatory drug (NSAID) that is widely used for the treatment of mild-to-moderate pain. Mefenamic acid belongs to the Biopharmaceutical Classification System (BCS) class II drug which has lower water solubility but high permeability. There are two different compendial methods available for dissolution tests of mefenamic acid solid dosage forms, i.e. methods of United States Pharmacopeia 37 (USP) and Pharmacopoeia of the People’s Republic of China 2010 ...

  17. Nonionic radiographic contrast media

    The invention deals with nonionic radiographic contrast media. The new media, which are water soluble and have desirable low osmolality properties, are derivates of the 5-amino-2,4,6-triiodine-1,3-benzenecarboxylic acid-unity where the 5-aminonitrogen atom is a part of a 4-, 5- or 6-membered heterocyclic ring

  18. Extraction and stripping behaviour of tri-iso-amyl phosphate and tri-n-butyl phosphate in n-dodecane with U(VI) in nitric acid media

    Batch extraction of U(VI) by 1.1 M solution of tri-iso-amyl phosphate (TiAP) in n-dodecane (n-DD) from uranyl nitrate solutions in nitric acid media has been investigated as a function of metal loading and equilibrium aqueous phase acidity at 303 K. A method adopted for free acidity determination by using a mixture of potassium oxalate and sodium fluoride for complexing U(VI) has been validated by comparing the data generated in the present study with literature data available for tri-n-butyl phosphate (TBP) under identical conditions. Extraction and stripping behaviour of 1.1 M TiAP/n-DD-U(VI)/HNO3 and 1.1 M TBP/n-DD-U(VI)/HNO3 systems have been compared by carrying out extraction, scrubbing and a series of stripping in cross-current mode. Stripping behaviour of both the solvents loaded with U(VI) and HNO3 has also been investigated as a function of time to understand the effects of nitric acid induced degradation on stripping.

  19. Amino Acid-Based Stabilization of Oxide Nanocrystals in Polar Media: From Insight in Ligand Exchange to Solution ¹H NMR Probing of Short-Chained Adsorbates.

    De Roo, Jonathan; Coucke, Sofie; Rijckaert, Hannes; De Keukeleere, Katrien; Sinnaeve, Davy; Hens, Zeger; Martins, José C; Van Driessche, Isabel

    2016-03-01

    Ligand exchange is a crucial step between nanocrystal synthesis and nanocrystal application. Although colloidal stability and ligand exchange in nonpolar media are readily established, the exchange of native, hydrophobic ligands with polar ligands is less systematic. In this paper, we present a versatile ligand exchange strategy for the phase transfer of carboxylic acid capped HfO2 and ZrO2 nanocrystals to various polar solvents, based on small amino acids as the incoming ligand. To gain insight in the fundamental mechanism of the exchange, we study this system with a combination of FTIR, zeta potential measurements, and solution (1)H NMR techniques. The detection of surface-associated, small ligands with solution NMR proves challenging in this respect. Tightly bound amino acids are undetectable, but their existence can be proven through displacement with other ligands in titration experiments. Alternatively, we find that methyl moieties belonging to bound species can circumvent these limitations because of their more favorable relaxation properties as a result of internal mobility. As such, our results are not limited to amino acids but to any short-chained ligand and will therefore facilitate the rigorous investigation and understanding of various ligand exchange processes. PMID:26854070

  20. The Correlation between Chitin and Acidic Mammalian Chitinase in Animal Models of Allergic Asthma

    Chia-Rui Shen

    2015-11-01

    Full Text Available Asthma is the result of chronic inflammation of the airways which subsequently results in airway hyper-responsiveness and airflow obstruction. It has been shown that an elicited expression of acidic mammalian chitinase (AMCase may be involved in the pathogenesis of asthma. Our recent study has demonstrated that the specific suppression of elevated AMCase leads to reduced eosinophilia and Th2-mediated immune responses in an ovalbumin (OVA-sensitized mouse model of allergic asthma. In the current study, we show that the elicited expression of AMCase in the lung tissues of both ovalbumin- and Der P2-induced allergic asthma mouse models. The effects of allergic mediated molecules on AMCase expression were evaluated by utilizing promoter assay in the lung cells. In fact, the exposure of chitin, a polymerized sugar and the fundamental component of the major allergen mite and several of the inflammatory mediators, showed significant enhancement on AMCase expression. Such obtained results contribute to the basis of developing a promising therapeutic strategy for asthma by silencing AMCase expression.

  1. Extraction and separation of beryllium (II) and aluminium (III) by di-(2-ethyl-hexyl)-phosphoric acid from sulphate media

    The distribution of Be(II) and Al(III) between aqueous sulphuric acid solutions and organic phases of di-(2-ethyl-hexyl)-phosphoric acid, has been investigated. The dependance of extraction on Psup(H) of aqueous phase, metal and extractant concentration as also on the diluent type, was thoroughly examined. A nuclear grade Be product is finally obtained

  2. Oxidative leaching process with cupric ion in hydrochloric acid media for recovery of Pd and Rh from spent catalytic converters

    Highlights: • A new leaching process based on Cu2+/HCl media for recovering Pd and Rh from spent autocatalytic converters is presented. • Palladium and rhodium were efficiently leached, with attained maximum yields of 95% and 86%, respectively. • Temperature, time, and HCl and Cu2+ concentrations were found to be significant factors in the leaching of Pd and Rh. - Abstract: The recycling of platinum-group metals from wastes such as autocatalytic converters is getting growing attention due to the scarcity of these precious metals and the market pressure originated by increase of demand in current and emerging applications. Hydrometallurgical treatment of such wastes is an alternative way to the most usual pyrometallurgical processes based on smelter operations. This paper focuses on the development of a leaching process using cupric chloride as oxidising agent, in HCl media, for recovery of palladium and rhodium from a spent catalyst. The chloride media allows the adequate conditions for oxidising and solubilising the metals, as demonstrated by equilibrium calculations based on thermodynamic data. The experimental study of the leaching process revealed that Pd solubilisation is clearly easier than that of Rh. The factors temperature, time, and HCl and Cu2+ concentrations were significant regarding Pd and Rh leaching, the latter requiring higher factor values to achieve the same results. Leaching yields of 95% Pd and 86% Rh were achieved under optimised conditions (T = 80 °C, t = 4 h, [HCl] = 6 M, [Cu2+] = 0.3 M)

  3. Oxidative leaching process with cupric ion in hydrochloric acid media for recovery of Pd and Rh from spent catalytic converters

    Nogueira, C.A., E-mail: carlos.nogueira@lneg.pt [Laboratório Nacional de Energia e Geologia, I.P., Campus do Lumiar, 1649-038 Lisboa (Portugal); Paiva, A.P., E-mail: appaiva@fc.ul.pt [Centro de Química e Bioquímica, Departamento de Química e Bioquímica, Faculdade de Ciências da Universidade de Lisboa, 1749-016 Lisboa (Portugal); Oliveira, P.C. [Laboratório Nacional de Energia e Geologia, I.P., Campus do Lumiar, 1649-038 Lisboa (Portugal); Costa, M.C., E-mail: mcorada@ualg.pt [Centro de Ciências do Mar, Departamento de Química e Farmácia, Faculdade de Ciências e de Tecnologia, Campus de Gambelas, 8005-139 Faro (Portugal); Costa, A.M. Rosa da, E-mail: amcosta@ualg.pt [Centro de Investigação em Química do Algarve, Departamento de Química e Farmácia, Faculdade de Ciências e de Tecnologia, Campus de Gambelas, 8005-139 Faro (Portugal)

    2014-08-15

    Highlights: • A new leaching process based on Cu{sup 2+}/HCl media for recovering Pd and Rh from spent autocatalytic converters is presented. • Palladium and rhodium were efficiently leached, with attained maximum yields of 95% and 86%, respectively. • Temperature, time, and HCl and Cu{sup 2+} concentrations were found to be significant factors in the leaching of Pd and Rh. - Abstract: The recycling of platinum-group metals from wastes such as autocatalytic converters is getting growing attention due to the scarcity of these precious metals and the market pressure originated by increase of demand in current and emerging applications. Hydrometallurgical treatment of such wastes is an alternative way to the most usual pyrometallurgical processes based on smelter operations. This paper focuses on the development of a leaching process using cupric chloride as oxidising agent, in HCl media, for recovery of palladium and rhodium from a spent catalyst. The chloride media allows the adequate conditions for oxidising and solubilising the metals, as demonstrated by equilibrium calculations based on thermodynamic data. The experimental study of the leaching process revealed that Pd solubilisation is clearly easier than that of Rh. The factors temperature, time, and HCl and Cu{sup 2+} concentrations were significant regarding Pd and Rh leaching, the latter requiring higher factor values to achieve the same results. Leaching yields of 95% Pd and 86% Rh were achieved under optimised conditions (T = 80 °C, t = 4 h, [HCl] = 6 M, [Cu{sup 2+}] = 0.3 M)

  4. Correlation between CMC and chromatographic index: simple and effective evaluation of the hydrophobic/hydrophilic balance of bile acids.

    Natalini, Benedetto; Sardella, Roccaldo; Camaioni, Emidio; Gioiello, Antimo; Pellicciari, Roberto

    2007-08-01

    The discovery that bile acids are involved in the modulation of nuclear steroid receptors has prompted renewed interest in this field of research. Due to the nature of research in this field, a technique that enables simple and effective assessment of the hydrophobic/hydrophilic balance, thus improving and speeding up evaluations of the biological profiles of these compounds, is greatly needed. In this context, both CMC value determination and RP-HPLC mobility evaluation were explored as possible approaches. While the CMC was calculated using the noninvasive conductimetric method, the RP-HPLC mobility was assessed by measuring the retention factor at several mobile phase compositions and extrapolating back to the pure aqueous mobile phase. The correlation of the CMC with the derived chromatographic hydrophobic index phi0 was satisfactory. PMID:17572887

  5. Correlations between the contents of phytic acid and inorganic phosphorous and downy mildew resistance of corn inbred lines

    Pantipa Na Chiangmai

    2015-10-01

    Full Text Available Seeds of corn inbred lines collected at the National Corn and Sorghum Research Center (NCSRC, Kasetsart University, were analyzed to determine the contents of phytic acid (PA and inorganic phosphorous (InP. These 28 and 29 inbred lines were cultivated at the NCSRC (in the 2008 late rainy season and 2009 early rainy season to evaluate their resistance to corn downy mildew caused by Peronosclerospora sorghi. Results showed that the values of the PA, InP contents and downy mildew infection were statistically different among these inbred lines in both seasons. However, there were no correlations between the contents of either PA or InP and downy mildew infection.

  6. Uptake and separation of thorium, scandium, europium, cobalt and zinc radiotracers by a filter paper loaded with di(2-ethylhexyl)phosphoric acid from different acid media

    The uptake of the radiotracers Th4+, Eu3+, Sc3+, Co2+ and Zn2+ by a filter paper loaded with di(2-ethylhexyl)phosphoric acid from different concentrations of HClO4, HCl, HNO3 and H2SO4 acids (10-2M - 8M) was investigated. Based on the experimental results, radiochemical procedures were developed for the interseparation of these radiotracers. (author)

  7. Serum uric acid levels correlate with atrial fibrillation in patients with chronic systolic heart failure

    ZHAO Qing-yan; YU Sheng-bo; HUANG He; CUI Hong-ying; QIN Mu; HUANG Ting; HUANG Cong-xin

    2012-01-01

    Background Studies have shown that increased levels of serum uric acid (SUA) are associated with atrial fibrillation (AF).However,less is known about the prognostic value of SUA levels for AF in patients with chronic heart failure (CHF).The aim of the study was to examine the prognostic value of SUA levels for AF in patients with CHF.Methods Sixteen thousand six hundred and eighty-one patients diagnosed with CHF from 12 hospitals were analyzed.Patients were categorized into AF group and non-AF group,death group,and survival group according to the results of the patients' medical records and follow-up.Univariate and multivariate Cox proportional hazards analyses were performed to examine the risk of AF.The sensitivity and specificity of SUA level in predicting the prognosis were examined by multivariate Cox models and receiver operating characteristic (ROC) curves.Results The results of univariate predictors in overall patients showed that the higher SUA level was associated with AF.SUA level (HR,1.084; 95% CI,1.017-1.144; P<0.001),diuretics (HR,1.549; 95% CI,1.246-1.854; P<0.001),and New York Heart Association (NYHA) (HR,1.237; 95% CI,1.168-1.306; P<0.001) function class were the independent risk factors for AF.The sensitivity and specificity of the models were 29.6% and 83.8% respectively for predicting AF.When SUA level was added to these models,it remained significant (Wald x2,1494.88; P <0.001 for AF); 58.8% (95% CI,57.7%-60.0%) of the observed results were concordant with the separate model.Conclusion Higher SUA level is associated strongly with AF in patients with CHF.SUA level can increase the sensitivity and specificity in predicting AF.

  8. Lipase-Catalyzed Esterification of Betulinic Acid Using Phthalic Anhydride in Organic Solvent Media: Study of Reaction Parameters

    M. Ghaffari Moghaddam

    2010-01-01

    Full Text Available The lipase from Candida antarctica immobilized on an acrylic resin (Novozym 435 was employed for the catalytic reaction of betulinic acid and phthalic anhydride. The influence of different reaction parameters, such as effect of single and mixed solvents, substrate molar ratio, reaction time, temperature, amount of enzyme, effect of inorganic bases and effect of substrate support were investigated and optimized. Optimum conditions to produce 3-O-phthalyl- betulinic acid were observed at reaction time; 24 h, temperature; 55°C, amount of enzyme; 176 mg, substrate molar ratio (betulinic acid: phthalic anhydride, 1:1, inorganic base of K2CO3, amount of celite; 170 mg in 1:1 mixture of chloroform and n-hexane as solvent. At optimum conditions, it gave 61.8% of 3-O-phthalyl- betulinic acid.

  9. The design of redox active thiol peroxidase mimics: Dihydrolipoic acid recognition correlates with cytotoxicity and prooxidant action.

    Zadehvakili, B; McNeill, S M; Fawcett, J P; Giles, G I

    2016-03-15

    Redox active molecules containing organoselenium or organotellurium groups catalyse the oxidation of cellular thiols by hydrogen peroxide and are currently being developed as therapeutic agents. Potentially these synthetic thiol peroxidase (TPx) mimics can protect cells from oxidative stress by catalysing the reduction of reactive oxygen species by the cellular thiol glutathione, an activity which mimics the function of the antioxidant enzyme glutathione peroxidase. Alternatively they can act as prooxidants by catalysing the oxidation of essential thiol species within the cell. However the structure-activity relationships which determine the choice of thiol substrate, and hence the overall antioxidant or prooxidant outcome of drug administration, remain unknown. We report the first study that relates the pharmacological properties of TPx mimics with their solubility and catalytic activity using different thiol substrates. We used a series of structurally related compounds PhMCnH2n+1 (M=Se, Te; n=4-7) and investigated their ability to catalyse the oxidation of the cellular thiols glutathione and dihydrolipoic acid by hydrogen peroxide. The resulting rate constants (kobs) were then related to compound cytotoxicity and antioxidant versus prooxidant action in A549 cancer cells. The results show that the dihydrolipoic acid kobs values correlate with both cytotoxicity and prooxidant function. This enabled us to define a relationship, IC50=10+280e(-5(DHLA)(kobs)()), which allows the prediction of TPx mimic cytotoxicity. In contrast, hydrophobicity and glutathione kobs were unrelated to the compounds' redox pharmacology. PMID:26801688

  10. Corrosion Inhibition and Adsorption Properties of Ethanolic Extract of Calotropis for Corrosion of Aluminium in Acidic Media

    Sudesh Kumar; Suraj Prakash Mathur

    2013-01-01

    The corrosion inhibition of aluminium in sulfuric acid solution in the presence of different plant parts, namely, leaves, latex, and fruit was studied using weight loss method and thermometric method. The ethanolic extracts of Calotropis procera and Calotropis gigantea act as an inhibitor in the acid environment. The inhibition efficiency increases with increase in inhibitor concentration. The plant parts inhibit aluminium, and inhibition is attributed, due to the adsorption of the plant part...

  11. Distribution coefficient correlations for nitric acid, U(VI) and Pu(IV) in two-phase system with aqueous nitric acid and 30% tri-n-butylphosphate solutions

    Distribution coefficient correlations are obtained for nitric acid, U(VI) and Pu(IV) extracted with 30% tri-n-butylphosphate (TBP) diluted by n-dodecane from aqueous nitric acid solutions. The correlation functions are described as a mathematical model that takes account of activity coefficients expressed by a function of ionic strength. The correlations include the temperature effect on distribution coefficient, and works successfully for the experimental distribution coefficients in the literature within the temperature range of 10 to 70degC. The concentrations of nitric acid, U(VI) and Pu(IV) in a multi-stage extraction experiment previously reported have been simulated well with the new distribution correlations at room and elevated temperatures. (author)

  12. THE CORRELATIONS OF RETINOIC ACID RECEPTOR-α AND ESTROGEN RECEPTOR EXPRESSION IN HUMAN BREAST CANCER CELL LINES AND TUMORS

    余黎明; 邵志敏; 蔡三军; 韩企夏; 沈镇宙

    1998-01-01

    Retinoic acid receptor-α(RAR α) plays a major role in the growth inhibitory effect of retinoic acid on human breast cancer ceils, may be it could serve as an indicator to guide the treatment and prevent of breast cancer with retinoic acid in ciiinc. All previous researchs were based on observing the changes ofRAR a mRAN expression. In this study, the expression of RAR a in human breast cell lines was studied by Northern Blot, Western Blot and Immunohistochemistry in mRNA level and protein level. Results showed that RAR a protein expression was correlated with RAR a mRNA expression. RAR α mRNA expression was higher in estrogen receptor (ER)-positive human breast cancer cell lines than in ER-negative ones. So was RAR α protein expression. Both RAR α mRNA amd RAR α protein expression were associated with ER status. The expression of RAR α and the relationship between RAR α and ER status were also determined by immunohistochemistry in 58 human primary breast cancer tumors. 37 (63.8%) tumors were ER-positive and of these 28 (75. 7%) were also RAR α -positive. The coexpression of ER and RAR α was statistleally significant (P<0. 01, by X2 contingency analysis), It was reported that RAR α expression in cultured breast cancer ceils was regulated by estrogen acting via the ER. Our study demonstrated that RAR α expression may be modulated in breast cancer in vivo by estrogen via ER.

  13. Deciphering Ascorbic Acid Regulatory Pathways in Ripening Tomato Fruit Using a Weighted Gene Correlation Network Analysis Approach

    Chao Gao; Zheng Ju; Shan Li; Jinhua Zuo; Daqi Fu; Huiqin Tian; Yunbo Luo; Benzhong Zhu

    2013-01-01

    Genotype is generally determined by the co-expression of diverse genes and multiple regulatory pathways in plants. Gene co-expression analysis combining with physiological trait data provides very important information about the gene function and regulatory mechanism. L-Ascorbic acid (AsA), which is an essential nutrient component for human health and plant metabolism, plays key roles in diverse biological processes such as cell cycle, cell expansion, stress resistance, hormone synthesis, and signaling. Here, we applied a weighted gene correlation network analysis approach based on gene expression values and AsA content data in ripening tomato (Solanum lycopersicum L.) fruit with different AsA content levels, which leads to identification of AsA relevant modules and vital genes in AsA regulatory pathways. Twenty-four modules were compartmentalized according to gene expression profiling. Among these modules, one negatively related module containing genes involved in redox processes and one positively related module enriched with genes involved in AsA biosynthetic and recycling pathways were further analyzed. The present work herein indicates that redox pathways as well as hormone-signal pathways are closely correlated with AsA accumulation in ripening tomato fruit, and allowed us to prioritize candidate genes for follow-up studies to dissect this interplay at the biochemical and molecular level.

  14. Correlation between serum uric acid levels and clinical characteristics in patients with longitudinally extensive transverse myelitis A case-control study

    Xiaofan You; Wei Qin; Jing Ye; Yonggang Hao; Wenhui Zhao; Wenli Hu

    2011-01-01

    Uric acid is reduced in demyelinating diseases, including multiple sclerosis and neuromyelitis optica (NMO).Longitudinally extensive transverse myelitis (LETM) is often an early manifestation of NMO.Whether uric acid levels are reduced at presentation of LETM remains unknown.The present study investigated serum uric acid levels by evaluating 35 patients with LETM, 64 with NMO, 62 with multiple sclerosis, 63 Mth other neurological diseases and 65 healthy controls.In addition, we tested the correlation between serum uric acid and the clinical characteristics of LETM.All patients were in the acute phase, defined as less than 1 month from onset or relapse.The results revealed that serum uric acid levels in LETM were significantly lower than in multiple sclerosis, other neurological diseases and healthy controls, but no difference was found between LETM and NMO.A negative correlation between uric acid levels and Expanded Disability Status Scale scores was found in LETM patients (r=-0.545, P < 0.05).The results suggest that uric acid levels are reduced in patients with LETM, raising the possibility that lower uric acid levels are an indicator of disease disability.Moreover, reduced uric acid levels may be a risk factor in NMO.

  15. Plasma bile acids show a positive correlation with body mass index and are negatively associated with cognitive restraint of eating in obese patients

    Philip ePrinz

    2015-06-01

    Full Text Available Bile acids may be involved in the regulation of food intake and energy metabolism. The aim of the study was to investigate the association of plasma bile acids with body mass index (BMI and the possible involvement of circulating bile acids in the modulation of physical activity and eating behavior. Blood was obtained in a group of hospitalized patients with normal weight (BMI 18.5-25 kg/m2, underweight (anorexia nervosa, BMI 50 kg/m2, n=14-15/group and plasma bile acid concentrations assessed. Physical activity and plasma bile acids were measured in a group of patients with anorexia nervosa (BMI 14.6±0.3 kg/m2, n=43. Lastly, in a population of obese patients (BMI 48.5±0.9 kg/m2, n=85, psychometric parameters related to disordered eating and plasma bile acids were assessed. Plasma bile acids showed a positive correlation with BMI (r=0.26, p=0.03 in the population of patients with broad range of BMI (9-85 kg/m2, n=74. No associations were observed between plasma bile acids and different parameters of physical activity in anorexic patients (p>0.05. Plasma bile acids were negatively correlated with cognitive restraint of eating (r=-0.30, p=0.008, while no associations were observed with other psychometric eating behavior-related parameters (p>0.05 in obese patients. In conclusion, these data may point towards a role of bile acids in the regulation of body weight. Since plasma bile acids are negatively correlated with the cognitive restraint of eating in obese patients, this may represent a compensatory adaptation to prevent further overeating.

  16. Plasma bile acids show a positive correlation with body mass index and are negatively associated with cognitive restraint of eating in obese patients.

    Prinz, Philip; Hofmann, Tobias; Ahnis, Anne; Elbelt, Ulf; Goebel-Stengel, Miriam; Klapp, Burghard F; Rose, Matthias; Stengel, Andreas

    2015-01-01

    Bile acids may be involved in the regulation of food intake and energy metabolism. The aim of the study was to investigate the association of plasma bile acids with body mass index (BMI) and the possible involvement of circulating bile acids in the modulation of physical activity and eating behavior. Blood was obtained in a group of hospitalized patients with normal weight (BMI 18.5-25 kg/m(2)), underweight (anorexia nervosa, BMI 50 kg/m(2), n = 14-15/group) and plasma bile acid concentrations assessed. Physical activity and plasma bile acids were measured in a group of patients with anorexia nervosa (BMI 14.6 ± 0.3 kg/m(2), n = 43). Lastly, in a population of obese patients (BMI 48.5 ± 0.9 kg/m(2), n = 85), psychometric parameters related to disordered eating and plasma bile acids were assessed. Plasma bile acids showed a positive correlation with BMI (r = 0.26, p = 0.03) in the population of patients with broad range of BMI (9-85 kg/m(2), n = 74). No associations were observed between plasma bile acids and different parameters of physical activity in anorexic patients (p > 0.05). Plasma bile acids were negatively correlated with cognitive restraint of eating (r = -0.30, p = 0.008), while no associations were observed with other psychometric eating behavior-related parameters (p > 0.05) in obese patients. In conclusion, these data may point toward a role of bile acids in the regulation of body weight. Since plasma bile acids are negatively correlated with the cognitive restraint of eating in obese patients, this may represent a compensatory adaptation to prevent further overeating. PMID:26089773

  17. Mathematical modeling of cadmium(II) solvent extraction from neutral and acidic chloride media using Cyanex 923 extractant as a metal carrier

    This paper describes experimental work and the mathematical modeling of solvent extraction of cadmium(II) from neutral and acidic aqueous chloride media with a Cyanex 923 extractant in Exxol D-100. Solvent extraction experiments were carried out to analyze the influence of variations in the composition of the aqueous and organic phases on the efficiency of cadmium(II) extraction. In neutral and acidic chloride conditions, the extraction of cadmium(II) by the organophosphorous extractant Cyanex 923 (L) is based on the solvation mechanism of neutral HnCdCl(2+n) species and the formation of HnCdCl(2+n)Lq complexes in the organic phase, where n = 0, 1, 2 and q = 1, 2. The mathematical model of cadmium(II) extraction was derived from the mass balances and chemical equilibria involved in the separation system. The model was computed with the Matlab software. The equilibrium parameters for metal extraction, i.e. the stability constants of the aqueous Cd-Cl complexes, the formation constants of the acidic Cd-Cl species and the metal equilibrium extraction constants, were proposed. The optimized constants were appropriate, as there was good agreement when the model was fitted to the experimental data for each of the experiments.

  18. S+X-I+ route to mesostructured materials from Fau and Beta zeolite precursors: A comparative study of their assembly behaviors in extremely acidic media

    Mesoporous molecular sieves were synthesized from Beta and Fau zeolite precursors through S+X-I+ route under extremely acidic conditions in parallel (designated as MBeta and MFau, respectively). The textural properties of MFau were different from its MBeta counterpart but resembled normal MCM-41 silica from TEOS. Al content in MBeta was almost equivalent to that in the initial Beta zeolite precursors, whereas only trace Al species was present in MFau from elemental analysis results. The hydrothermal stability of MBeta after post-synthesis ammonia treatment was considerably improved compared with normal MCM-41 aluminosilicates, whereas the MFau after the same procedure was as unstable as normal MCM-41 silica. Thus, the assembly behaviors of Beta and Fau zeolite precursors were comparatively studied based on these results. The microstructure of Fau zeolite precursors were degraded by the extremely acidic condition, and Al species was dissolved into the synthesis mixture. However, Beta zeolite precursors survived the chemical attack of extremely acidic media and were incorporated into mesostructured framework as primary building units

  19. Polyethylene Glycols as Efficient Media for Decarboxylative Nitration of α,β-Unsaturated Aromatic Carboxylic Acids by Ceric Ammonium Nitrate in Acetonitrile Medium: A Kinetic and Mechanistic Study

    K. Ramesh

    2013-01-01

    Full Text Available Polyethylene glycols (PEGs were found to be efficient media for decarboxylative nitration of α,β-unsaturated aromatic carboxylic acids by ceric ammonium nitrate (CAN in acetonitrile to give β-nitrostyrene derivatives. Kinetics of the reaction exhibited second order kinetics with a first order dependence on [CAN] and [substrate]. Reactions were too sluggish to be studied in the absence of PEG; therefore detailed kinetics were not taken up. Reaction times were reduced from 24 hrs to few hours. The catalytic activity was found to be in the increasing order PEG-300 > PEG-400 > PEG-600 > PEG-200. Mechanism of PEG-mediated reactions was explained by Menger-Portnoy's scheme as applied in micellar kinetics.

  20. Immunohistochemical analysis of retinoic acid receptor-alpha in human breast tumors: retinoic acid receptor-alpha expression correlates with proliferative activity.

    van der Leede, B. M.; Geertzema, J.; Vroom, T. M.; Décimo, D.; Lutz, Y.; van der Saag, P. T.; van der Burg, B.

    1996-01-01

    Retinoids are known to prevent mammary carcinogenesis in rodents and inhibit the growth of human breast cancer cells in vitro. Previously we demonstrated that retinoid inhibition of proliferation of human breast cancer cell lines is largely mediated by retinoic acid receptor (RAR)-alpha. In this study we describe for the first time the histological distribution of RAR-alpha in 33 breast lesion specimens as determined by immunostaining with RAR-alpha antibody. Nuclear staining was observed in tumor tissue and normal portions of the breast samples. Connective tissue exhibited relative uniform staining, whereas a wide range of RAR-alpha expression was found in the epithelial tumor cells. RAR-alpha protein was expressed at significantly higher levels in tumors with greater proliferative activity as determined by immunostaining with Ki-67 antibody. This suggests that RAR-alpha expression may be altered with tumor progression. Although a positive correlation between RAR-alpha mRNA levels and estrogen receptor status of breast tumors has previously been documented, we did not find such a relationship at the protein level. As RAR-alpha plays a major role in retinoid-mediated growth inhibition of human breast cancer cell in vitro, our findings suggest that patients with highly proliferating tumors could be responsive to retinoid independently of their responsiveness to (anti)-estrogens. Images Figure 1 Figure 2 PMID:8669476

  1. Synthesis of Poly(methacrylic acid)-functionalized SBA-15 and its Adsorption of Phenol in Aqueous Media

    Poly(methacrylic acid)-functionalized SBA-15 silicas (denoted as P-x-PMA/SBA-15 where x is molar ratio of TSPM/(TEOS+TSPM) in percentage in the initial mixture) were synthesized by co-condensation of tetraethoxysilane and varying contents of 3-(trimethoxysilyl)propyl methacrylate in acidic medium with the block copolymer Pluronic 123 as a structure directing agent and then polymerization by methacrylic acid in the presence of ammonium persulfate as an initiator. The functionalized materials were characterized by PXRD, TEM, SEM, IR, and N2 adsorption-desorption at 77 K. The investigation of phenol adsorption in aqueous solution on the materials showed that the poly(methacrylic acid)-functionalized mesoporous silicas possess strong adsorption ability for phenol with interaction of various kinds of hydrogen bonds. The adsorption data were fitted to Langmuir isotherms and the maximum adsorption capacity of the three functionalized materials P-5-PMA/SBA-15, P-10-PMA/SBA-15, and P-15-PMA/SBA-15 to be 129.37 mg/g, 187.97 mg/g, and 78.43 mg/g, respectively, were obtained. The effect of the pH on phenol adsorption was studied

  2. Synthesis of Poly(methacrylic acid)-functionalized SBA-15 and its Adsorption of Phenol in Aqueous Media

    Vo, Vien; Kim, Heejun; Kim, Hayeong; Kim, Youngmee; Kim, Sung Jin [Ewha Womans Univ., Seoul (Korea, Republic of)

    2013-12-15

    Poly(methacrylic acid)-functionalized SBA-15 silicas (denoted as P-x-PMA/SBA-15 where x is molar ratio of TSPM/(TEOS+TSPM) in percentage in the initial mixture) were synthesized by co-condensation of tetraethoxysilane and varying contents of 3-(trimethoxysilyl)propyl methacrylate in acidic medium with the block copolymer Pluronic 123 as a structure directing agent and then polymerization by methacrylic acid in the presence of ammonium persulfate as an initiator. The functionalized materials were characterized by PXRD, TEM, SEM, IR, and N{sub 2} adsorption-desorption at 77 K. The investigation of phenol adsorption in aqueous solution on the materials showed that the poly(methacrylic acid)-functionalized mesoporous silicas possess strong adsorption ability for phenol with interaction of various kinds of hydrogen bonds. The adsorption data were fitted to Langmuir isotherms and the maximum adsorption capacity of the three functionalized materials P-5-PMA/SBA-15, P-10-PMA/SBA-15, and P-15-PMA/SBA-15 to be 129.37 mg/g, 187.97 mg/g, and 78.43 mg/g, respectively, were obtained. The effect of the pH on phenol adsorption was studied.

  3. The correlation between urinary 5-hydroxyindoleacetic acid and sperm quality in infertile men and rotating shift workers

    Pariente José A

    2010-11-01

    Full Text Available Abstract Background Serotonin is a neurotransmitter that modulates a wide range of neuroendocrine functions. However, excessive circulating serotonin levels may induce harmful effects in the male reproductive system. The objective of this study was to evaluate whether the levels of urinary 5-hydroxyindoleacetic acid (5-HIIA, a major serotonin metabolite, correlate with different classical seminal parameters. Methods Human ejaculates were obtained from 40 men attending infertility counselling and rotating shift workers by masturbation after 4-5 days of abstinence. Urinary 5- HIIA concentration was quantified by using a commercial ELISA kit. Forward motility was assessed by a computer-aided semen analysis (CASA system. Sperm concentration was determined using the haemocytometer method. Sperm morphology was evaluated after Diff-Quik staining, while sperm vitality was estimated after Eosin-Nigrosin vital staining. Results Our results show that urinary 5-HIIA levels obtained from a set of 20 volunteers negatively correlated with sperm concentration, forward motility, morphology normal range and sperm vitality. On the other hand, we checked the relationship between male infertility and urinary 5-HIIA levels in 20 night shift workers. Thus, urinary 5-HIIA levels obtained from 10 recently-proven fathers were significantly lower than those found in 10 infertile males. Additionally, samples from recent fathers exhibited higher sperm concentration, as well as better forward motility and normal morphology rate. Conclusions In the light of our findings, we concluded that high serotonin levels, indirectly measured as urinary 5-HIIA levels, appear to play a role as an infertility determinant in male subjects.

  4. Competition and Commercial Media Bias

    BLASCO, A.; F. Sobbrio

    2011-01-01

    This paper reviews the empirical evidence on commercial media bias (i.e., advertisers influence over media accuracy) and then introduces a simple model to summarize the main elements of the theoretical literature. The analysis provides three main policy insights for media regulators: i) Media regulators should target their monitoring efforts towards news contents upon which advertisers are likely to share similar preferences; ii) In advertising industries characterized by high correlation in ...

  5. Increased palmitoyl-myristoyl-phosphatidylcholine in neonatal rat surfactant is lung specific and correlates with oral myristic acid supply.

    Bernhard, Wolfgang; Raith, Marco; Pynn, Christopher J; Gille, Christian; Stichtenoth, Guido; Stoll, Dieter; Schleicher, Erwin; Poets, Christian F

    2011-08-01

    Surfactant predominantly comprises phosphatidylcholine (PC) species, together with phosphatidylglycerols, phosphatidylinositols, neutral lipids, and surfactant proteins-A to -D. Together, dipalmitoyl-PC (PC16:0/16:0), palmitoyl-myristoyl-PC (PC16:0/14:0), and palmitoyl-palmitoleoyl-PC (PC16:0/16:1) make up 75-80% of mammalian surfactant PC, the proportions of which vary during development and in chronic lung diseases. PC16:0/14:0, which exerts specific effects on macrophage differentiation in vitro, increases in surfactant during alveolarization (at the expense of PC16:0/16:0), a prenatal event in humans but postnatal in rats. The mechanisms responsible and the significance of this reversible increase are, however, not understood. We hypothesized that, in rats, myristic acid (C14:0) enriched milk is key to lung-specific PC16:0/14:0 increases in surfactant. We found that surfactant PC16:0/14:0 in suckling rats correlates with C14:0 concentration in plasma chylomicrons and lung tissue triglycerides, and that PC16:0/14:0 fractions reflect exogenous C14:0 supply. Significantly, C14:0 was increased neither in plasma PC, nor in liver triglycerides, free fatty acids, or PC. Lauric acid was also abundant in triglycerides, but was not incorporated into surfactant PC. Comparing a C14:0-rich milk diet with a C14:0-poor carbohydrate diet revealed increased C14:0 and decreased C16:0 in plasma and lung triglycerides, respectively. PC16:0/14:0 enrichment at the expense of PC16:0/16:0 did not impair surfactant surface tension function. However, the PC profile of the alveolar macrophages from the milk-fed animals changed from PC16:0/16:0 rich to PC16:0/14:0 rich. This was accompanied by reduced reactive oxygen species production. We propose that nutritional supply with C14:0 and its lung-specific enrichment may contribute to decreased reactive oxygen species production during alveolarization. PMID:21636561

  6. The inhibition action of N-furfuryl-N'-phenyl thiourea on the corrosion of mild steel in acid media

    H. V. SUDHAKER NAYAK

    2006-10-01

    Full Text Available The inhibiting effect of N-furfuryl-N'-phenyl thiourea (FPTU on the corrosion of mild steel in aqueous solutions of 0.05 and 0.1MHCl, as well as 0.025 and 0.05 M H2SO4 has been demonstrated using the potentiodynamic polarization technique. The polarization data showed that FPTU acts as an efficient anodic inhibitor for mild steel in both acid solutions. Avery high inhibition efficiency was evidenced in both acid solutions and it was found to vary with the concentration of the inhibitor and temperature. The obtained kinetic parameters of adsorption revealed spontaneous adsorption and a strong interaction of FPTU with the mild steel surface.

  7. Electrodeposition of ruthenium, rhodium and palladium from nitric acid and ionic liquid media: Recovery and surface morphology of the deposits

    Research highlights: → Platinum group metals are man-made noble metals. → Electrochemical recovery of fission platinoids. → Recovery from nitric acid medium. → Recovery from ionic liquid medium. → Platinoids with exotic surface morphologies. - Abstract: Electrodeposition is a promising technique for the recovery of platinum group metals with unique surface morphologies. The electrodeposition of palladium, ruthenium and rhodium from aqueous nitric acid, and non-aqueous 1-butyl-3-methylimidazolium chloride ionic liquid medium was studied at stainless steel electrode. The surface morphology and elemental composition of the resultant deposit were probed by scanning electron microscopy (SEM) and energy dispersive X-ray (EDS) analysis. Deposits with diverse surface morphologies and metal compositions were obtained by varying the composition of the electrolytic medium and applied potential. The results demonstrate the possibility of tailoring the morphologies of PGMs by controlling the composition and potential needed for electrodeposition.

  8. Media Pedagogy: Media Education, Media Socialisation and Educational Media

    Lars Qvortrup

    2007-01-01

    The aim of this paper is to examine the relationship between education and media. These two concepts can be combined in three ways: one can think of media education, i.e. education in the subject of mass media. One can think of media socialisation, i.e. education within the context of a media society in which pupils and students are experienced media users. Finally, one can think of educational media, i.e. media used for educational purposes.After having specified these three subject areas, t...

  9. Glyoxylic acid as catalyst: A simple selective synthesis of 1,2-disubstituted benzimidazoles in aqueous media

    Shivaji S. Pawar; Deepak V. Dekhane; Murlidhar S. Shingare; Shivaji N. Thore

    2008-01-01

    Glyoxylic acid (5 tool%) performs as a novel highly water-soluble catalyst for the synthesis of 2-aryl-l-arylmethyl-lH-benzimidazoles from a wide range of substituted o-phenylenediamines and various substituted aldehydes in good to excellent isolated yields (85-95%) using water as solvent at ambient temperature. The remarkable advantages offered by this method are easily and inexpensive available catalyst, simple procedure, mild conditions, much faster (20-40 min) reactions and excellent yields of products.

  10. Perfluorinated carboxylic and sulphonic acids in surface water media from the regions of Tibetan Plateau: Indirect evidence on photochemical degradation?

    Yamazaki, Eriko; Falandysz, Jerzy; Taniyasu, Sachi; Hui, Ge; Jurkiewicz, Gabriela; Yamashita, Nobuyoshi; Yang, Yong-Liang; Lam, Paul K S

    2016-01-01

    Perfluorinated surfactants and repellents are synthetic substances that have found numerous industrial and customer applications. Due to their persistence, at least two groups of these substances-perfluorinated carboxylic acids (PFCAs) and perfluorinated sulfonic acids (PFSAs)-are diffused widely in the environment. It is hypothesized that the Tibetan Plateau, is one of few unique places on the Earth, due to its topography, specifically the vast space and high elevation above sea level, geographic location, climate, high solar radiation, lack of industry, little urbanization and general lack of significant direct sources of pollution. There it is believed possible to gain an insight into atmospheric fate (possible photochemical degradation of higher molecular mass and formation of lower molecular mass PFCAs and PFSAs) of PFASs under un-disturbed environmental conditions. Ultratrace analytical method for PFCAs and PFSAs and use of transportation and field blanks, laboratory blanks and isotopically labelled surrogates for recovery control has allowed the determination of nine perfluorinated carboxylic acids and six perfluorinated sulfonic acids at ultra-trace levels in water based samples from the alpine dimension regions of the Tibetan Plateau, the eastern slope of Minya Konka peak at the eastern edge of the Tibetan Plateau, and also from the city of Chengdu from the lowland of the Sichuan Province in China. The specific compositional pattern of PFCAs and PFSAs and low levels of pollution with those compounds were observed in the central region of the Tibetan Plateau and in the region adjacent to the peaks of Minya Konka in the Eastern Tibetan Plateau. The fingerprint of the compositional pattern of PFCAs and PFSAs in water samples in the central region of the Tibetan Plateau and in the alpine region adjacent to the peaks of Minya Konka in the Eastern Tibetan Plateau may be explained by the result of photochemical degradation with dealkylation of longer chain

  11. Porous media investigation before and after hydrochloric acid injection on a pre-salt carbonate coquinas sample.

    Machado, A C; Teles, A P; Pepin, A; Bize-Forest, N; Lima, I; Lopes, R T

    2016-04-01

    Porous space characterization of carbonate rocks is an important aid in petroleum exploration from carbonate reservoir. In this study, X-ray microtomography technique was applied to evaluate total porosity of a coquina sample extracted from pre-salt reservoir, in Brazil, before and after acid injection. Two image processing program were used in order to assess performance. The results showed that microtomography has potential to compute porosity of coquina samples and provides information about rock porous network. PMID:26794261

  12. Experimental Study and Numerical Solution of Poly Acrylic Acid Supported Magnetite Nanoparticles Transport in a One-Dimensional Porous Media

    M. Golzar; S. F. Saghravani; Azhdari Moghaddam, M.

    2014-01-01

    Recently, iron nanoparticles have attracted more attention for groundwater remediation due to its potential to reduce subsurface contaminants such as PCBs, chlorinated solvents, and heavy metals. The magnetic properties of iron nanoparticles cause to attach to each other and form bigger colloid particles of iron nanoparticles with more rapid sedimentation rate in aqueous environment. Using the surfactants such as poly acrylic acid (PAA) prevents iron nanoparticles from forming large flocs tha...

  13. The complete genome sequence of Natrinema sp. J7-2, a haloarchaeon capable of growth on synthetic media without amino acid supplements.

    Feng, Jie; Liu, Bin; Zhang, Ziqian; Ren, Yan; Li, Yang; Gan, Fei; Huang, Yuping; Chen, Xiangdong; Shen, Ping; Wang, Lei; Tang, Bing; Tang, Xiao-Feng

    2012-01-01

    Natrinema sp. J7-2 is an extreme haloarchaeon capable of growing on synthetic media without amino acid supplements. Here we report the complete genome sequence of Natrinema sp. J7-2 which is composed of a 3,697,626-bp chromosome and a 95,989-bp plasmid pJ7-I. This is the first complete genome sequence of a member of the genus Natrinema. We demonstrate that Natrinema sp. J7-2 can use gluconate, glycerol, or acetate as the sole carbon source and that its genome encodes complete metabolic pathways for assimilating these substrates. The biosynthetic pathways for all 20 amino acids have been reconstructed, and we discuss a possible evolutionary relationship between the haloarchaeal arginine synthetic pathway and the bacterial lysine synthetic pathway. The genome harbors the genes for assimilation of ammonium and nitrite, but not nitrate, and has a denitrification pathway to reduce nitrite to N(2)O. Comparative genomic analysis suggests that most sequenced haloarchaea employ the TrkAH system, rather than the Kdp system, to actively uptake potassium. The genomic analysis also reveals that one of the three CRISPR loci in the Natrinema sp. J7-2 chromosome is located in an integrative genetic element and is probably propagated via horizontal gene transfer (HGT). Finally, our phylogenetic analysis of haloarchaeal genomes provides clues about evolutionary relationships of haloarchaea. PMID:22911826

  14. Removal of CdTe in acidic media by magnetic ion-exchange resin: a potential recycling methodology for cadmium telluride photovoltaic waste.

    Zhang, Teng; Dong, Zebin; Qu, Fei; Ding, Fazhu; Peng, Xingyu; Wang, Hongyan; Gu, Hongwei

    2014-08-30

    Sulfonated magnetic microspheres (PSt-DVB-SNa MPs) have been successfully prepared as adsorbents via an aqueous suspension polymerization of styrene-divinylbenzene and a sulfonation reaction successively. The resulting adsorbents were confirmed by means of Fourier transform infrared spectra (FT-IR), X-ray diffraction (XRD), transmission electron microscope (TEM), scanning electron microscope equipped with an energy dispersive spectrometer (SEM-EDS) and vibrating sample magnetometer (VSM). The leaching process of CdTe was optimized, and the removal efficiency of Cd and Te from the leaching solution was investigated. The adsorbents could directly remove all cations of Cd and Te from a highly acidic leaching solution of CdTe. The adsorption process for Cd and Te reached equilibrium in a few minutes and this process highly depended on the dosage of adsorbents and the affinity of sulfonate groups with cations. Because of its good adsorption capacity in strong acidic media, high adsorbing rate, and efficient magnetic separation from the solution, PSt-DVB-SNa MPs is expected to be an ideal material for the recycling of CdTe photovoltaic waste. PMID:25128764

  15. Enhanced expression of polysialic acid correlates with malignant phenotype in breast cancer cell lines and clinical tissue samples.

    Wang, Xin; Li, Xiang; Zeng, Ying-Nan; He, Fa; Yang, Xiao-Min; Guan, Feng

    2016-01-01

    Polysialic acid (PSA) is highly expressed during embryonic development, but barely expressed during postnatal development, and may be 're-expressed' in cancer tissues. In this study, motility and migration assays were performed to compare the changes in cell behavior between non-malignant and maligant cells. Next, the expression levels of PSA were evaluated in 4 human and mouse normal breast or breast cancer (BC) cell lines using 1,2-diamino-4,5-methylenedioxybenzene-labeling HPLC technology, as well as in human clinical BC tissue samples. PSA expression was significantly higher in malignant cells (where it appeared to facilitate cell migration and motility) than in non-malignant cells. Enhanced PSA expression levels were also observed during epithelial-mesenchymal transition (EMT), a leading cause of cancer cell metastasis, which was induced in the NMuMG and MCF10A cells by treatment with transforming growth factor-β1 (TGF-β1). An increased PSA expression also correlated with the disease stage in the patients with BC (PPST) and polysialyltransferase ST8SiaII (STX), which are responsible for PSA synthesis, were differently expressed in the tested BC samples. However, PST, but not STX, was re-expressed in 14 out of 20 clinical BC samples. The findings of the present study indicate that the pathophysiology of BC involves the aberrant regulation of PSA expression and PST gene expression. PMID:26530860

  16. Electrochemical characterization of the protective film formed by the unsymmetrical Schiff's base on the mild steel surface in acid media

    The corrosion inhibition efficiency of a newly synthesized Schiff's base for the corrosion of mild steel was studied in 1.0 M HCl and 0.5 M H2SO4 solutions. The results of weight loss measurements, electrochemical impedance and potentiodynamic polarization measurements consistently demonstrated that the Schiff's base synthesized is a good corrosion inhibitor with an inhibitory efficiency of approximately 92% at an optimum inhibitor concentration of 600 mg/L. The inhibition in both of the corrosive media was observed to be a mixed type. The potential of zero charge (PZC) at the metal-solution interface was determined for both the inhibited and uninhibited solutions to provide the mechanism of inhibition. The inhibitor formed a film on the metal surface through chloride or sulfate bridges depending upon the medium. The temperature dependence of the corrosion rate was also studied in the temperature range from 27 to 50 oC. The value of the activation energy (Ea) calculated showed that the inhibition film formation on the metal surface occurred through chemisorption. The thermodynamic parameters such as the adsorption equilibrium constant (Kads) and the free energy of adsorption (ΔGads) were calculated and discussed. Several adsorption isotherms were tested and the experimental data fit well with the Langmuir adsorption isotherm.

  17. Synergistic extraction of gadolinium from nitrate media by mixtures of bis (2,4,4-trimethylpentyl) dithiophosphinic acid and di-(2-ethylhexyl) phosphoric acid

    Highlights: • The effect of operating parameters on the gadolinium extraction was investigated. • The mixture of extractants had the synergistic effects on the gadolinium extraction. • Mixture system obtained better stripping in comparison with D2EHPA system. - Abstract: The extraction of gadolinium (III) from aqueous nitrate solution with bis (2,4,4-trimethylpentyl) dithiophosphinic acid (Cyanex301), di-(2-ethylhexyl) phosphoric acid (D2EHPA) and the mixtures of extractants was investigated. Various parameters affecting the extraction process including the pH of aqueous phase, nitrate ion, extractant concentration, temperature, and stripping agents were studied. The stoichiometric coefficients of reactive extraction, thermodynamic and equilibrium parameters were obtained for two extractants and their mixtures. The results showed that the extraction ability of Cyanex301 was lower than that of D2EHPA extractant. As a result, the extraction of Gd3+ at low concentration of Cyanex301 was investigated by the addition of D2EHPA to the extraction system. The reactive extraction in the mixture system was spontaneous in nature as referred to the negative sign of ΔG while it was not favorable in case of single Cyanex301 system as indicated by the positive sign of ΔG. The experimental results showed that the mixture of extractants provided better extraction efficiency and effective stripping performance in comparison with single D2EHPA or Cyanex301 system

  18. Extraction of molybdenum by the di-n-butyl 2.2.N.hydroxyhexanamide (tri-n-butylacetohydroxamic acid) from aqueous acidic media

    The design of a new industrial process for the production of the fission product 99 Mo, led to study of the extraction of 99Mo(VI) by the tri-n-butylacetohydroxamic acid (TBAH). Due to the large affinity of TBAH for Mo(VI), the study was conducted with unusual experimental conditions : the concentrations of the extracting molecule and metallic ion were very low, typically CTBAH = 10-5 M and CMo(VI) = 10-8 M. The overall extraction system was described using a mathematical model quite simple, which, in particular, takes into account all the Mo(VI) species present in the aqueous phase. When the extractions were carried out from a perchloric acid medium, two different extraction mechanisms of Mo(VI) were identified : for CHC104 3, the extraction of Mo(VI) corresponds to a cationic exchange, whereas for CHC104 > 3 mol/dm3, a neutral Mo(VI) compound is extracted. Moreover it was found that the extracting system Mo(VI)/TBAH is extremely sensitive to the temperature. It is thus possible to change the way of the transfer of Mo(VI) between the two phases, by control of the temperature of the mixture : the extraction is carried out at room temperature and the back-extraction at elevated temperature

  19. Cholecystectomy in patients with normal gallbladder function did not alter characteristics in duodenal motility which was not correlated to size of bile acid pool

    Andersen, P V; Mortensen, J; Oster-Jørgensen, E;

    1999-01-01

    Nine gallstone patients with normal gallbladder function as assessed by hepatobiliary scintigraphy were included. Fasting and postprandial duodenal motility were studied before and one month after an uncomplicated laparoscopic cholecystectomy. An ambulatory continuous pressure recording was......, cholecystectomy does not alter duodenal motility, which was not correlated to the size of the bile acid pool....

  20. An electrochemical study for corrosion inhibition of iron by some organic phosphonium chloride derivatives in acid media

    The inhibiting action of (chloromethyl) triphenyl phosphonium chloride (CTP), tetraphenyl phosphonum chloride (TP), triphenyl phosphine oxide (TPO), triphenyl (phenylmethyl) phosphonium chloride (TPM) and triphenyl phosphine (TPP) on the corrosion of iron in 1 M HCl solution was studied using potentiodynamic polarization and electrochemical impedance spectroscopy (EIS). Experimental results revealed that CTP, TP, TPO, and TPM act as inhibitors for iron in acid environments, while TPP is an accelerator. These compounds are mixed-type inhibitors and the inhibition efficiency increased with increasing concentrations. Equivalent circuits of the investigated systems are suggested

  1. Production of a-amylase in acid cheese whey culture media with automatic pH control

    Ferreyra Rosana; Lorda Graciela; Balatti Antonio

    1998-01-01

    The influence of aeration and automatic pH control on the production of a-amylase by a strain of Bacillus subtilis NRRL 3411 from acid cheese whey was studied. Tests were carried out in a rotary shaker and in mechanically stirred fermenters. a-amylase was analysed according to DUN?s method. Oxygen absorption rate was determined by Cooper?s method. Cell oxygen demand was determined as oxygen consumption in a Warburg respirometer. The level of dissolved oxygen was measured by means of a galvani...

  2. Extraction of actinides and fission products by octyl(phenyl)-N,N-diisobutylcarbamoylmethyl-phosphine oxide from nitric acid media.

    Mathur, J N; Murali, M S; Natarajan, P R; Badheka, L P; Banerji, A

    1992-05-01

    Extraction of promethium(III), uranium(VI), plutonium(IV), americium(III), zirconium(IV), ruthenium(III), iron(III) and palladium(II) has been carried out with a mixture of octyl(phenyl)-N,N-diisobutylcarbamoylmethylphosphine oxide (CMPO) and tributyl phosphate (TBP) in dodecane. The effects of nitric acid, TBP and CMPO concentrations on the extraction of these metal ions have been studied. The nature of the species of the above metal ions extracted into the organic phase has been suggested. PMID:18965406

  3. Sugar and Acid Content and Their Genotypic Correlations of Unselected P.Persica x P.Davidiana Progenies as Affected by Hairness and Flesh Color

    WU Ben-hong; LI Shao-hua; Quilot Bénédicte; Génard Michel; Kervella Jocelyne

    2004-01-01

    Fruit sugar and acid content were determined in a group of hybrids from one family,including 22 peach and 85 nectarine genotypes, or 75 white-fleshed and 32 yellow-fleshed genotypes. Sucrose accounted for about 65% of the total sugar, and malate for about 50%of the total acid. Mean sucrose, fructose, sorbitol, total sugar, soluble solid and quinate content were significantly higher in nectarines than in peaches, while no significant difference was found in mean malate, citrate and total acid content between nectarines and peaches. Shikimate content was very low and ranged from 0.011-0.046 meq 100 g-1 FW in all genotypes studied. Flesh color did not affect sugar and acid content.Glucose and fructose had a close positive correlation (r=0.63***). Malate had positive correlations with sucrose, sorbitol, total sugar and soluble solid content. The correlation between citrate and sugars were not significant. Glucose, fructose, sorbitol and malate content seemed to be higher in late-maturing genotypes. Sucrose, total sugar and total acid content had a parabolic relationship with developmental period (from full blooming date to maturity date).

  4. Breath Ethane Concentrations in Healthy Volunteers Correlate with a Systemic Marker of Lipid Peroxidation but Not with Omega-3 Fatty Acid Availability

    Brian M. Ross

    2014-07-01

    Full Text Available Ethane in human breath derives from lipid peroxidation, specifically the reaction between omega-3 fatty acids and reactive oxygen species. It has been proposed to be a non-invasive marker of oxidative stress, a deleterious process which may play an important role in the pathophysiology of several common diseases. It is unclear, however, whether ethane concentration actually correlates with systemic oxidative stress or whether it is primarily a marker of airway biochemistry. To investigate this possibility the breath ethane concentrations in 24 healthy volunteers were compared to that of a systemic measure of oxidative stress, plasma hydroperoxides, as well as to blood concentrations of the lipophilic anti-oxidant vitamin E, and the abundance of omega-3 fatty acids. Breath ethane concentrations were significantly (p < 0.05 positively correlated with blood hydroperoxide concentrations (rp = 0.60 and negatively with that of vitamin E (rp = −0.65, but were not correlated with either the total omega-3 fatty acid concentration (rp = −0.22 or that of any individual species of this fatty acid class. This data supports the hypothesis that breath ethane is a marker of systemic lipid peroxidation, as opposed to that of omega-3 fatty acid abundance.

  5. Complexation of Cu(II) by original tartaric acid-based ligands in nonionic micellar media: thermodynamic study and applications.

    Dupont-Leclercq, Laurence; Giroux, Sébastien; Parant, Stéphane; Khoudour, Leïla; Henry, Bernard; Rubini, Patrice

    2009-04-01

    The complexation of Cu(II) with original alkylamidotartaric acids (C(x)T) is investigated in homogeneous aqueous medium and in the presence of nonionic micelles of Brij 58 (C16EO20), thanks to various analytical techniques such as NMR self-diffusion experiments, CD and UV-vis spectroscopy, ESI mass spectrometry, pHmetry and micellar-enhanced ultrafiltration (MEUF). First, a complete speciation study proves the formation of dimeric complexes in water and provides their formation constants. Second, a similar study is led in the presence of nonionic micelles. It underlines a modification of the apparent equilibrium constants in micellar medium and demonstrates that the structure of the complexes is slightly modified in the presence of micelles. This thermodynamic and structural study is applied to modelize the evolution of the extraction yields of Cu(II) by the micelles as a function of pH and to identify the complexes extracted in the micelles. The effects of the chain length of the ligand (C3T vs C8T) on the solubilization properties are put into relief and discussed. Anionic species are proved to be more incorporated in the nonionic micelles than the cationic species. The extracting system constituted of octylamidotartaric acid (CsT) solubilized in nonionic micelles of Brij 58 is demonstrated to be very efficient for the extraction of Cu(II) by MEUF, this technique being an interesting green alternative to traditional solvent extraction. PMID:19708239

  6. Experimental Measurements and Correlations Isobaric Vapor-Liquid Equilibria for Water + Acetic Acid + Sec-butyl Acetate at 101.3 kPa

    LI Ling; HE Yong; WU Yanxiang; ZOU Wenhu

    2013-01-01

    Isobaric vapor-liquid equilibrium(VLE) data for acetic acid + sec-butyl acetate and water + acetic acid + sec-butyl acetate systems were determined at 101.3 kPa using a modified Rose type.The nonideality of the vapor phase caused by the association of the acetic acid was corrected by the chemical theory and Hayden-O'Connell method.Thermodynamic consistency was tested for the binary VLE data.The experimental data were correlated successfully with the Non-Random Two Liquids (NRTL) model.The Root Mean Square Deviation (RMSD) of the ternary system was 0.0038.The saturation vapor pressure of sec-butyl acetate at 329 to 385 K was measured by means of two connected equilibrium cells.The vapor pressures of water and sec-butyl acetate were correlated with the Antoine equation.The binary interaction parameters and the ternary VLE data were obtained from this work.

  7. Correlation study of microalgae carbonation in membrane integrated photobioreactor

    Suali, E.; Sarbatly, R.; Shaleh, S. R. M.; Lahin, F. A.; Anisuzzaman, S. M.

    2016-06-01

    Microalgae ability to utilise CO2 higher compared to terrestrial plant making it suitable for biomass production and as CO2 utiliser. This could be one of many ways to preserve a safer and healthier environment with less air pollutant. For study purposes, CO2 usually transported to microalgae culture broth with the aid of membrane technology to prevent formation of large bubble and to accelerate the carbonation of microalgal media. However, membrane susceptible to accumulation of CO2, which can cause extreme acidic to microalgal media. This prevents microalgae to assimilate CO2. Thus, this study proposes correlations to prevent the extreme acidic: which represents the relationship of: (1) CO2 inlet and accumulation, (2) CO2 inlet and CO2 at the membrane-liquid interphase and (3) CO2 inlet and CO2 solubility in the media. The correlations were successfully validated with a deviation of less than 20% compared to the theoretical value.

  8. Sorption isotherms of europium captured on supports impregnated with dicarbollide and dibutyldiethyl carbamoylmethylphosphonate from nitric acid media and column experiments

    The concentration dependence was investigated for the sorption of europium (10-6 to 10-2 mol/l) on the XAD-7 support impregnated with 25 wt.% chlorinated dicarbollic acid and 5 wt.% dibutylether carbamoylmethylphosphonate. The sorption proceeded from 0.1 M and 1 M HNO3 in static conditions or from 0.1 M HNO3 in laboratory columns in dynamic conditions. The distribution coefficients were found to decrease substantially at higher Eu concentrations, and their values obtained in dynamic conditions were two-fold lower than in the static conditions. The effective capacity of the sorbent for Eu was concentration-dependent, and no saturation was reached in the experiments performed. The desorption of Eu from columns using 0.15 M EDTA solutions with an initial pH of 7.02 was also examined at 40 ± 5 deg. 2 tabs., 6 figs., 6 refs

  9. Corrosion Inhibitive Evaluation of an Environmentally Friendly Water-Base Acrylic Terpolymer on Mild Steel in Hydrochloric Acid Media

    Azghandi, Mojtaba Vakili; Davoodi, Ali; Farzi, Gholam Ali; Kosari, Ali

    2013-12-01

    The corrosion inhibitive performance of an environmentally friendly water-base acrylic terpolymer [methyl methacrylate/Butyl Acrylate/Acrylic acid (ATP)] on mild steel in 1 M HCl was investigated by alternating current and direct current electrochemical techniques and the quantum chemical method. An efficiency of more than 97 pct was obtained with 0.8 mmol/L ATP. The increase in inhibitor concentration and immersion time has a positive effect, while the temperature influence is negligible on the inhibitor efficiency. The present terpolymer obeys the Langmuir isotherm, and thermodynamic calculation reveals a chemisorption type on the surface. Density functional calculations showed that the lone pairs of electrons of oxygen in the structure of three monomers are suitable sites to adsorb onto the metal surface. Finally, in the presence of ATP, a decrease in surface roughness and corrosion attacks was demonstrated by atomic force microscopy and optical microscopy examinations, respectively.

  10. Kinetics of Corrosion Inhibition of Aluminum in Acidic Media by Water-Soluble Natural Polymeric Pectates as Anionic Polyelectrolyte Inhibitors

    Refat M. Hassan

    2013-06-01

    Full Text Available Corrosion inhibition of aluminum (Al in hydrochloric acid by anionic polyeletrolyte pectates (PEC as a water-soluble natural polymer polysaccharide has been studied using both gasometric and weight loss techniques. The results drawn from these two techniques are comparable and exhibit negligible differences. The inhibition efficiency was found to increase with increasing inhibitor concentration and decrease with increasing temperature. The inhibition action of PEC on Al metal surface was found to obey the Freundlich isotherm. Factors such as the concentration and geometrical structure of the inhibitor, concentration of the corrosive medium, and temperature affecting the corrosion rates were examined. The kinetic parameters were evaluated and a suitable corrosion mechanism consistent with the kinetic results is discussed in the paper.

  11. Kinetics of hydrogen evolution at tantalum electrode in sulfuric acid media: effects of pH and solution temperature

    The influence of temperature in the range of 20-80 deg C and sulfuric acid and potassium sulfate solution pH in the range of pH=1.81-3.0 on kinetics of electrochemical reaction of hydrogen evolution on tantalum, which is characterized by Ta-H high binding energy, has been studied. It has been ascertained that the reaction occurs on the surface of electrode covered by a thin film of tantalum oxide. The oxide is preserved during cathode polarization, only its electrophysical and adsorption al properties change at the expense of hydrogen atoms penetration to the oxide film volume and appearance of low-valency; tantalum cations in the oxide

  12. Quantum chemical and experimental characterization of the effect of ziprasidone on the corrosion inhibition of steel in acid media

    Highlights: → Acid corrosion inhibition. → Effective at very small concentration. → The effect of indole moiety in ziprasidone towards the corrosion inhibition. → Evaluation by quantum chemical and electrochemical methods. → Adsorption sites, planarity and LUMO orbitals of ziprasidone. - Abstract: Ziprasidone is composed of the benzisothiozole-3-piperizine (BITP) and an indole moiety. The inhibition potential of ziprasidone for the corrosion of steel in 1.0 M HCl and 0.5 M H2SO4 was assessed by weight loss, polarisation, electrochemical impedance spectroscopy and quantum methods. The results showed that nearly 10 times lower concentration of ziprasidone showed the same efficiency that was rendered by BITP. This is related to the planarity of ziprasidone molecule, potential adsorption sites and the extensive distribution of LUMO orbitals on indole moiety which cause larger back donation. Ziprasidone follow Langmuir adsorption isotherm.

  13. Evil Media

    Fuller, Matthew; Goffey, Andrew (translated by)

    2012-01-01

    Evil Media develops a philosophy of media power that extends the concept of media beyond its tried and trusted use in the games of meaning, symbolism, and truth. It addresses the gray zones in which media exist as corporate work systems, algorithms and data structures, twenty-first century self-improvement manuals, and pharmaceutical techniques. Evil Media invites the reader to explore and understand the abstract infrastructure of the present day. From search engines to flirting strategies, f...

  14. Media education.

    Strasburger, Victor C

    2010-11-01

    The American Academy of Pediatrics recognizes that exposure to mass media (eg, television, movies, video and computer games, the Internet, music lyrics and videos, newspapers, magazines, books, advertising) presents health risks for children and adolescents but can provide benefits as well. Media education has the potential to reduce the harmful effects of media and accentuate the positive effects. By understanding and supporting media education, pediatricians can play an important role in reducing harmful effects of media on children and adolescents. PMID:20876180

  15. Benchmark ab Initio Conformational Energies for the Proteinogenic Amino Acids through Explicitly Correlated Methods. Assessment of Density Functional Methods.

    Kesharwani, Manoj K; Karton, Amir; Martin, Jan M L

    2016-01-12

    The relative energies of the YMPJ conformer database of the 20 proteinogenic amino acids, with N- and C-termination, have been re-evaluated using explicitly correlated coupled cluster methods. Lower-cost ab initio methods such as MP2-F12 and CCSD-F12b actually are outperformed by double-hybrid DFT functionals; in particular, the DSD-PBEP86-NL double hybrid performs well enough to serve as a secondary standard. Among range-separated hybrids, ωB97X-V performs well, while B3LYP-D3BJ does surprisingly well among traditional DFT functionals. Treatment of dispersion is important for the DFT functionals; for the YMPJ set, D3BJ generally works as well as the NL nonlocal dispersion functional. Basis set sensitivity for DFT calculations on these conformers is weak enough that def2-TZVP is generally adequate. For conformer corrections to heats of formation, B3LYP-D3BJ and especially DSD-PBEP86-D3BJ or DSD-PBEP86-NL are adequate for all but the most exacting applications. The revised geometries and energetics for the YMPJ database have been made available as Supporting Information and should be useful in the parametrization and validation of molecular mechanics force fields and other low-cost methods. The very recent dRPA75 method yields good performance, without resorting to an empirical dispersion correction, but is still outperformed by DSD-PBEP86-D3BJ and particularly DSD-PBEP86-NL. Core-valence corrections are comparable in importance to improvements beyond CCSD(T*)/cc-pVDZ-F12 in the valence treatment. PMID:26653705

  16. An in vitro-in vivo correlation study for nifedipine immediate release capsules administered with water, alcoholic and non-alcoholic beverages: Impact of in vitro dissolution media and hydrodynamics.

    Mercuri, A; Fares, R; Bresciani, M; Fotaki, N

    2016-02-29

    The impact of hydrodynamics and media composition on nifedipine dissolution profile from IR (immediate release) soft capsules was investigated using dissolution apparatus USP1, USP2, USP3 and USP4 (United State Pharmacopoeia). Media composition was varied in terms of pH and content, to mimic the dosage form intake with water or non-alcoholic beverages (orange juice) and alcoholic beverages (orange juice/ethanol mixture (47% v/v)). Through construction of in vitro-in vivo correlations (IVIVC) with corresponding in vivo data from the literature, it was possible to evaluate the in vitro conditions that are likely to simulate the in vivo formulation behaviour. Both linear and nonlinear correlations were obtained depending on experimental set-ups. Testing of 20mg nifedipine capsules in FaSSGFst (Fasted State Simulated Gastric Fluid pH 1.6; water administration) produced IVIVC with the USP3 (after time scaling) and USP4 apparatus. IVIVC were obtained for USP2, USP3 and USP4 in FaSSGFoj (Fasted State Simulated Gastric Fluid pH 3.4; orange juice administration). Linear and nonlinear correlations were obtained with the USP1, USP2 and USP3 apparatus when testing the capsules in FaSSGFoj/EtOH (orange juice/ethanol administration). This study highlighted that selection of physiologically relevant dissolution set-ups is critical for predicting the in vivo impact of formulations co-administration with water, non-alcoholic and alcoholic beverages. PMID:26721731

  17. Optimization and effect of dairy industrial waste as media components in the production of hyaluronic acid by Streptococcus thermophilus.

    Mohan, Naresh; Balakrishnan, Rengesh; Sivaprakasam, Senthilkumar

    2016-08-17

    Hyaluronic acid (HA) production using a dairy industrial waste is a more cost-efficient strategy than using an expensive synthetic medium. In this study, we investigated the production of HA using Streptococcus thermophilus under shake flask conditions using dairy industrial waste as nutritional supplements, namely whey permeate (WP) and whey protein hydrolysate (WPH). Preliminary screening using Plackett-Burman design exhibited WP, WPH, initial pH, and inoculum size as significant factors influencing HA titer. Response surface methodology design of four factors was formulated at three levels for enhanced production of HA. Shake flask HA fermentation by S. thermophilus was performed under global optimized process conditions and the optimal HA titer (342.93 mg L(-1)) corroborates with Box-Behnken design prediction. The molecular weight of HA was elucidated as 9.22-9.46 kDa. The ultralow-molecular weight HA reported in this study has a potential role in drug and gene delivery applications. PMID:26681350

  18. Synergistic extraction of U(VI) and Th(IV) from nitric acid media HBMPPT and TBP in toluene

    The synergistic extraction of U(VI) and Th(IV) from nitric acid solution by HBMPPT (4-benzoyl-2,4-dihydro-5-methyl-2-phenyl-3H-pyrazol-3-thione) and TBP (tributylphosphate) in toluene was studied. The extraction ability of HBMPPT for U(VI) and Th(IV) was not so high, but when a little TBP was added in, the ability to extract U(VI) and Th(IV) was improved. The extracted complexes may be presented as UO2NO3·BMPPT·TBP and UO2(BMPPT)2·TBP for U(VI), and Th(NO3)3·BMPPT·TBP and Th(NO3)2(BMPPT)2·TBP for Th(IV), respectively, in the synergistic extraction system. The synergistic effect of HBMPPT and TBP makes the separation coefficient of U(VI)/Th(IV) or U(VI)/Eu(III) reach a high value

  19. Experimental and quantum chemical studies on two triazole derivatives as corrosion inhibitors for mild steel in acid media

    Li, W.; Tian, H.; Hou, B. [Key Laboratory of Corrosion Science, Shandong, Institute of Oceanology, Chinese Academy of Sciences, Qingdao (China); Hu, L.; Tao, Z. [College of Chemistry and Chemical Engineering, Chongqing University, Chongqing (China)

    2011-11-15

    Two triazole derivatives [1-phenyl-2-(5-(1,2,4) triazol-1-ylmethyl-(1,3,4) oxadizaol-2-ylsulphanyl)-ethanone (PTOE) and 2-(4-tert-butyl-benzylsulphanyl)-5-(1,2,4) triazol-1-ylmethyl-(1,3,4) oxadiazole (TBTO)] were synthesized as new corrosion inhibitors for the corrosion of mild steel in 1 M hydrochloric acid solutions. The inhibiting efficiency of the different inhibitors was evaluated by means of weight loss and electrochemical techniques such as electrochemical impedance spectroscopy (EIS) and polarization curves. The electrochemical investigation results indicate that these compounds act as mixed-type inhibitors retarding the anodic and cathodic corrosion reactions and do not change the mechanism of either hydrogen evolution reaction or mild steel dissolution. The studied compounds followed the Langmuir adsorption isotherm, and the thermodynamic parameters were determined and discussed. The effect of molecular structure on the inhibition efficiency has been investigated with ab initio calculations. The electronic properties such as highest occupied molecular orbital (HOMO) energy level, lowest unoccupied molecular orbital (LUMO) energy level, dipole moment ({mu}) and molecular orbital densities were calculated. (Copyright copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  20. Analysis of the formation of Ta2O5 passive films in acid media through mechanistic modeling

    Electrochemical impedance spectroscopy (EIS) analyses are carried out to evaluate the passive features of tantalum oxide films (Ta2O5) formed at different potentiostatic conditions (0.5, 1.0, 1.5 and 2.0 V vs SSE). A supporting electrolyte of 0.1 M H2SO4 (pH 1) has been used to emulate acidic corrosive conditions for the growth of films with an n-type electronic character. A modification of the point defect model (PDM) accounting for the formation of molecular hydrogen (blistering damage) is used to fit the experimental EIS diagrams, and obtain the kinetic parameters that best describe the semiconductive behavior of the passive films. After this analysis, diffusivities in the order of 5.37 ± 1.6 x 10-17 and 1.98 ± 1.4 x 10-20 cm2 s-1 were obtained for the oxygen (DVO··) and hydroxyl vacancies (DVOH·), respectively. These findings show the capabilities of the EIS and the physicochemical modeling to account for the formation of valve-metal oxide films on a different range of conditions.

  1. Transport of ARS-labeled hydroxyapatite nanoparticles in saturated granular media is influenced by surface charge variability even in the presence of humic acid

    Highlights: ► The transport and retention kinetics of ARS-labeled hydroxyapatite nanoparticles (ARS-nHAP) were investigated over a range of ionic strengths in the presence of humic acid. ► A two-site kinetic attachment model predicted both the breakthrough curves and retention profiles of ARS-nHAP quite well. ► The retention profiles of ARS-nHAP exhibited hyperexponential shapes for all the test conditions. ► Surface charge heterogeneities on the collector surfaces and especially within the ARS-nHAP population contributed to hyperexponential retention profiles. - Abstract: Hydroxyapatite nanoparticle (nHAP) is increasingly being used to remediate soils and water polluted by metals and radionuclides. The transport and retention of Alizarin red S (ARS)-labeled nHAP were investigated in water-saturated granular media. Experiments were carried out over a range of ionic strength (Ic, 0–50 mM NaCl) conditions in the presence of 10 mg L−1 humic acid. The transport of ARS-nHAP was found to decrease with increasing suspension Ic in part, because of enhanced aggregation and chemical heterogeneity. The retention profiles (RPs) of ARS-nHAP exhibited hyperexponential shapes (a decreasing rate of retention with increasing transport distance) for all test conditions, suggesting that some of the attachment was occurring under unfavorable conditions. Surface charge heterogeneities on the collector surfaces and especially within the ARS-nHAP population were contributing causes for the hyperexponential RPs. Consideration of the effect(s) of Ic in the presence of HA is needed to improve the efficacy of nHAP for scavenging metals and actinides in real soils and groundwater environments.

  2. Characterization and corrosion behavior of electroless Ni-P/nano-SiC coating inside the CO2 containing media in the presence of acetic acid

    In this research, Ni-P and Ni-P/nano-SiC coatings were applied on the X70 steel substrate successfully without any surfactant. Then, CO2 corrosion in the presence of acetic acid (HAc) was investigated using electrochemical techniques. Scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS) and X-ray diffraction (XRD) techniques were used for surface analyses of the coatings. The electrochemical behavior of corrosion was investigated using polarization test and electrochemical impedance spectroscopy (EIS). XRD pattern of Ni-P/nano-SiC coating was very similar to that of Ni-P coating. EDS results demonstrated the presence of SiC particles in the coating. SEM images confirmed the presence of SiC nano-particles with almost uniform distribution in the coating. The corrosion current density was less in the Ni-P and Ni-P/nano-SiC coated samples than uncoated X70 steel. Ni-P/nano-SiC coated sample had the most corrosion resistance because of less effective metallic area available for corrosive media. The overall protection mechanism of Ni-P and Ni-P/nano-SiC coatings was achieved by formation of a layer of adsorbed hypophosphite anions (H2PO2-).

  3. Experimental and theoretical investigation of the adsorption behaviour of new triazole derivatives as inhibitors for mild steel corrosion in acid media

    Three triazole derivatives (4-chloro-acetophenone-O-1'-(1',3',4'-triazolyl)-metheneoxime (CATM), 4-methoxyl-acetophenone-O-1'-(1',3',4'-triazolyl)-metheneoxime (MATM) and 4-fluoro-acetophenone-O-1'-(1',3',4'-triazolyl)-metheneoxime (FATM)) have been synthesized as new inhibitors for the corrosion of mild steel in acid media. The inhibition efficiencies of these inhibitors were evaluated by means of weight loss and electrochemical techniques such as electrochemical impedance spectroscopy (EIS) and polarization curves. Then the surface morphology was studied by scanning electron microscopy (SEM). The adsorption of triazole derivatives is found to obey Langmuir adsorption isotherm, and the thermodynamic parameters were determined and discussed. The relationship between molecular structure of these compounds and their inhibition efficiency has been investigated by ab initio quantum chemical calculations. The electronic properties such as the highest occupied molecular orbital (HOMO), the lowest unoccupied molecular orbital (LUMO) energy levels, energy gap (LUMO-HOMO), dipole moment and molecular orbital densities were computed

  4. Sono-assisted photocatalytic degradation of styrene-acrylic acid copolymer in aqueous media with nano titania particles and kinetic studies.

    Saien, J; Delavari, H; Solymani, A R

    2010-05-15

    The ultrasonic irradiation (28 kHz, 50 W) in pre-cavitations regime was employed to enhance the degradation rate of styrene-acrylic acid copolymer in aqueous media with nano titania photocatalyst particles. A stainless steel cylindrical sono-photo reactor with capacity of about 1.25 L, equipped with a UV lamp (250 W) was used. The influence of operational parameters, i.e. catalyst concentration, pH and temperature was studied and the role of active species was also distinguished. For an initial substrate concentration of 30 mg L(-1), under mild applied conditions of 30 mg L(-1) of photocatalyst, 25 degrees C and natural pH, a degradation and mineralization conversion of 96% and 91%, respectively, was achieved using sono-assisted photocatalysis process in about only 60 min. These efficiencies are much higher than those obtained with only photocatalysis process. Meanwhile, the threshold of cavitations was found corresponded to catalyst concentration of about 70 mg L(-1). Kinetic studies based on Langmuir-Hinshelwood and power law models in addition to the results from radical scavenger usage revealed that for sono-assisted process, the substrate undergoes degradation mainly via electron-hole redox on the surface of titania particles. It is while for the only photocatalysis process, the reaction proceeds via hydroxyl radicals in the solution bulk. PMID:20092940

  5. Media Literacy

    Gelu Mihai LEICU; Laura Rita PITARIU

    2015-01-01

    Media are part of our lives today. Our pupils watch TV, play online games, blog, upload videos on YouTube, use Facebook, etc. Messages transmitted by the media flow constantly into our and their minds. Media literacy provides us with a range of information and abilities which help us analyse, evaluate, and even create messages in various modes of the media. Students are encouraged to think critically about the media they consume. Hobbs has found out that media literacy implies: a set of skill...

  6. Correlations between periparturient serum concentrations of non-esterified fatty acids, beta-hydroxybutyric acid, bilirubin, and urea and the occurrence of clinical and subclinical postpartum bovine endometritis

    Tenhagen Bernd-Alois; Drillich Marc; Kaufmann Toschi B; Heuwieser Wolfgang

    2010-01-01

    Abstract Background Postpartum endometritis in cattle is a multifactorial disease with high economic impact. Both, clinical endometritis (CE) and subclinical endometritis (SCE) result in decreased reproductive performance. Results from in vitro studies led to the implication that non-esterified fatty acids (NEFA), beta-hydroxybutyric acid (BHBA), bilirubin, and urea could be used as predictors for endometritis in veterinary practice. In this field study, we set out to establish optimal predic...

  7. Cationic speciation in nonaqueous media

    Electronic spectra of solutions of d transition elements in the superacids HF, H2SO4, HSO3F, and CF3SO3H and in chloroaluminate melts indicate that in acidic monaqueous media the elements are present as solvated cations, whereas in basic media the speciation is anionic, the same situation as in aqueous solutions. Further, in very highly acidic media, cations in very low oxidation states are stable (e.g., Ti2+), but these disproportionate on addition of base to the system. In this paper spectra, where available, of U, Np, and Pu in oxidation states III and IV in aqueous media, in protonic superacids, and in chloroaluminates are presented to postulate cationic speciation of these early actinides in highly acidic media

  8. Common carotid intima media thickness and ankle-brachial pressure index correlate with local but not global atheroma burden: a cross sectional study using whole body magnetic resonance angiography.

    Jonathan R Weir-McCall

    Full Text Available Common carotid intima media thickness (CIMT and ankle brachial pressure index (ABPI are used as surrogate marker of atherosclerosis, and have been shown to correlate with arterial stiffness, however their correlation with global atherosclerotic burden has not been previously assessed. We compare CIMT and ABPI with atheroma burden as measured by whole body magnetic resonance angiography (WB-MRA.50 patients with symptomatic peripheral arterial disease were recruited. CIMT was measured using ultrasound while rest and exercise ABPI were performed. WB-MRA was performed in a 1.5T MRI scanner using 4 volume acquisitions with a divided dose of intravenous gadolinium gadoterate meglumine (Dotarem, Guerbet, FR. The WB-MRA data was divided into 31 anatomical arterial segments with each scored according to degree of luminal narrowing: 0 = normal, 1 = <50%, 2 = 50-70%, 3 = 70-99%, 4 = vessel occlusion. The segment scores were summed and from this a standardized atheroma score was calculated.The atherosclerotic burden was high with a standardised atheroma score of 39.5±11. Common CIMT showed a positive correlation with the whole body atheroma score (β 0.32, p = 0.045, however this was due to its strong correlation with the neck and thoracic segments (β 0.42 p = 0.01 with no correlation with the rest of the body. ABPI correlated with the whole body atheroma score (β -0.39, p = 0.012, which was due to a strong correlation with the ilio-femoral vessels with no correlation with the thoracic or neck vessels. On multiple linear regression, no correlation between CIMT and global atheroma burden was present (β 0.13 p = 0.45, while the correlation between ABPI and atheroma burden persisted (β -0.45 p = 0.005.ABPI but not CIMT correlates with global atheroma burden as measured by whole body contrast enhanced magnetic resonance angiography in a population with symptomatic peripheral arterial disease. However this is

  9. Nontraditional Cardiovascular Biomarkers and Estimation of Cardiovascular Risk in Predialysis Chronic Kidney Disease Patients and Their Correlations With Carotid Intima Media Thickness

    Sathi, Satyanand; Mahapatra, Himanshu; Sunder, Sham; Jayaraman, Rajesh; Sharma, Neera; Verma, Himanshu; Krishnamoorthy, Venkataramanan; Gupta, Anurag; Kanchi, Prabhu; Daksh, Sunil; Pursnani, Lalit; Shadab, Faisal; Singh, Manveer

    2014-01-01

    Background: Cardiovascular biomarkers such as N-terminal pro-B-type natriuretic peptide (NT-proBNP), cardiac troponin T (cTnT), hs-CRP (high sensitivity C-reactive protein), and albuminuria predict underlying heart disease in the general population as well as CKD patients. Objectives: We aimed to study the association of NT-proBNP, cTnT, hs-CRP, and spot urine albumin creatinine ratio with carotid intima media thickness (CIMT) for cardiovascular risk estimation in predialysis CKD (chronic kid...

  10. Nonalcoholic Fatty Liver Disease: Correlation of the Liver Parenchyma Fatty Acid with Intravoxel Incoherent Motion MR Imaging-An Experimental Study in a Rat Model.

    Seung-Man Yu

    Full Text Available To prospectively evaluate the changes in fatty acid concentration after administrating a 60% high-fat diet to a non-alcoholic fatty liver disease rat model and to perform a correlation analysis between fatty acid with molecular diffusion (Dtrue, perfusion-related diffusion (Dfast, and perfusion fraction (Pfraction.This prospective study was approved by the appropriate ethics committee. Ten male Sprague-Dawley rats were fed a 60% high-fat diet until the study was finished. Point-resolved spectroscopy sequence 1H-MRS with TR = 1,500 msec, TE = 35 msec, NEX = 64, and 8×8×8 mm3 voxel was used to acquire magnetic resonance spectroscopy (MRS data. Diffusion-weighted imaging was performed on a two-dimensional multi-b value spin echo planar image with the following parameters: repetition time msec/echo time msec, 4500 /63; field of view, 120×120 msec2; matrix, 128×128; section thickness, 3 mm; number of repetition, 8; and multiple b value, 0, 25, 50, 75, 100, 200, 500, 1000 sec/mm2. Baseline magnetic resonance imaging and magnetic resonance spectroscopy data (control were acquired. 1H proton MRS and diffusion-weighted imaging were obtained every 2 weeks for 8 weeks. The individual contributions of the true molecular diffusion and the incoherent motions of water molecules in the capillary network to the apparent diffusion changes were estimated using a least-square nonlinear fitting in MatLab. A Wilcoxon signed-rank test with the Kruskal-Wallis test was used to compare each week's fatty acid mean quantification. Spearman's correlation coefficient was used to evaluate the correlation between each fatty acid (e.g., total lipid (TL, total saturated fatty acid (TSFA, total unsaturated fatty acid (TUSFA, total unsaturated bond (TUSB, and polyunsaturated bond (PUSB and intravoxel incoherent motion (IVIM mapping images (e.g., Dtrue, Dfast, and Pfraction.The highest mean TL value was at week 8 (0.278 ± 0.10 after the administration of the 60% high-fat diet

  11. Correlating phospholipid fatty acids (PLFA) in a landfill leachate polluted aquifer with biogeochemical factors by multivariate statistical methods

    Ludvigsen, Liselotte; Albrechtsen, Hans-Jørgen; Rootzén, Helle; Christensen, Thomas Højlund

    Different multivariate statistical analyses were applied to phospholipid fatty acids representing the biomass composition and to different biogeochemical parameters measured in 37 samples from a landfill contaminated aquifer at Grindsted Landfill (Denmark). Principal component analysis and...... correspondence analysis were used to identify groups of samples showing similar patterns with respect to biogeochemical variables and phospholipid fatty acid composition. The principal component analysis revealed that for the biogeochemical parameters the first principal component was linked to the pollution...... acids, different groups of samples and outliers were revealed by the principal component analysis. The principal component analysis on data in absolute concentrations revealed that many phospholipid fatty acids reflected the pollution effect on the biomass composition. In contrast, the phospholipid...

  12. Correlating phospholipid fatty acids (PLFA) in a landfill leachate polluted aquifer with biogeochemical factors by multivariate statistical methods

    Ludvigsen, Liselotte; Albrechtsen, Hans-Jørgen; Rootzén, Helle;

    1997-01-01

    acids, different groups of samples and outliers were revealed by the principal component analysis. The principal component analysis on data in absolute concentrations revealed that many phospholipid fatty acids reflected the pollution effect on the biomass composition. In contrast, the phospholipid......Different multivariate statistical analyses were applied to phospholipid fatty acids representing the biomass composition and to different biogeochemical parameters measured in 37 samples from a landfill contaminated aquifer at Grindsted Landfill (Denmark). Principal component analysis and...... effect and to redox processes and the second principal component described the geological and geochemical features of the samples. Dependent on the data transformation of the phospholipid fatty acid profiles in either absolute concentrations (logarithm transformed) or in mol% of total phospholipid fatty...

  13. Ethyl group as matrix modifier and inducer of ordered domains in hybrid xerogels synthesised in acidic media using ethyltriethoxysilane (ETEOS) and tetraethoxysilane (TEOS) as precursors

    Hybrid silica xerogels favourably combine the properties of organic and inorganic components in one material; consequently these materials are useful for multiple applications. The versatility and mild synthetic conditions provided by the sol-gel process are ideal for the synthesis of hybrid materials. The specific aims of this study were to synthesise hybrid xerogels in acidic media using tetraethoxysilane (TEOS) and ethyltriethoxysilane (ETEOS) as silica precursors, and to assess the role of the ethyl group as a matrix modifier and inducer of ordered domains in xerogels. All xerogels were synthesised at pH 4.5, at 60 °C, with 1:4.75:5.5 TEOS:EtOH:H2O molar ratio. Gelation time exponentially increased with the ETEOS molar ratio. Incorporation of the ethyl groups into the structure of xerogels reduced cross-linking, increased the average siloxane bond length, and promoted the formation of ordered domains. As a result, a transition from Qn to Tn signals detected in the 29Si NMR spectra, the Si–O structural band in the FTIR spectra shifted to lower wavelength, and a new peak in the XRD pattern at 2θ < 10° appeared in the XRD patterns. Mass spectroscopy detected fragments with high numbers of silicon atoms and a polymeric distribution. - Graphical abstract: Display Omitted - Highlights: • Hybrid xerogels were synthesised for ETEOS/TEOS mixtures up to 80% ETEOS. • The gelification time exponentially increased with ETEOS content. • FTIR, XRD and MAS NMR demonstrated the presence of ethyl groups into xerogels. • For ETEOS contents ≤30%, ethyl group acted as matrix modifier. • For ETEOS contents ≥30%, ethyl groups induced the formation of ordered domains

  14. Genetically determined serum levels of mannose-binding lectin correlate negatively with common carotid intima-media thickness in systemic lupus erythematosus

    Troelsen, Lone N; Garred, Peter; Christiansen, Buris; Torp-Pedersen, Christian; Jacobsen, Søren

    2010-01-01

    Patients with systemic lupus erythematosus (SLE) have excess cardiovascular morbidity and mortality due to accelerated atherosclerosis that cannot be attributed to traditional cardiovascular risk factors alone. Variant alleles of the mannose-binding lectin gene (MBL2) causing low serum concentrat......Patients with systemic lupus erythematosus (SLE) have excess cardiovascular morbidity and mortality due to accelerated atherosclerosis that cannot be attributed to traditional cardiovascular risk factors alone. Variant alleles of the mannose-binding lectin gene (MBL2) causing low serum...... concentrations of functional mannose-binding lectin (MBL) are associated with SLE and development of atherosclerosis. Recent studies show that these variant alleles are associated with increased risk of arterial thrombosis and cardiovascular disease in patients with SLE. Intima-media thickness of the common...

  15. Correlation of dynamic contrast-enhanced magnetic resonance imaging with histologic tumor grade: comparison of macromolecular and small-molecular contrast media

    Background. The endothelial integrity of microvessels is disrupted in malignant tumors. Quantitative assays of tumor microvascular characteristics based on dynamic magnetic resonance imaging (MRI) were correlated with histopathologic grade in mammary soft tissue tumors. Materials and methods. A spectrum of tumors, benign through highly malignant, was induced in 33 female rats by administration of N -ethyl-N -nitrosourea (ENU), a potent carcinogen. Dynamic contrast-enhanced MRI was performed using a small-molecular contrast medium [gadopentetate, MW = 0.5 kDa] and a macromolecular contrast medium [albumin-(Gd-DTPA)30, MW = 92 kDa] at an interval of 1-2 days. Permeability surface area product (PS), as estimated by the corresponding endothelial transfer coefficient (KPS), and fractional plasma volume (fPV) were calculated for each tumor and each contrast agent using a two-compartment bi-directional kinetic model. MRI microvascular characteristics were correlated with histopathologic tumor grade. Results. Tumor permeability to macromolecular contrast medium, characterized by KPS, showed a highly positive correlation with tumor grade (r 2 = 0.76, P -10). K PS values were zero for all benign and some low-grade carcinomas, greater than zero in all other carcinomas, and increased in magnitude with higher tumor grade. A considerably smaller but significantly positive correlation was found between fPV and tumor grade using macromolecular contrast medium (r 2 = 0.25, P PS or fPV values and tumor grade was found using gadopentetate (r 2 = 0.01, P > 0.95 and r 2 = 0.03, P > 0.15, respectively). Conclusion. Quantitative tumor microvascular permeability assays generated with macromolecular MRI contrast medium correlate closely with histologic tumor grade. No significant correlation is found using small-molecular gadopentetate. (orig.)

  16. Reconstructing random media

    We formulate a procedure to reconstruct the structure of general random heterogeneous media from limited morphological information by extending the methodology of Rintoul and Torquato [J. Colloid Interface Sci. 186, 467 (1997)] developed for dispersions. The procedure has the advantages that it is simple to implement and generally applicable to multidimensional, multiphase, and anisotropic structures. Furthermore, an extremely useful feature is that it can incorporate any type and number of correlation functions in order to provide as much morphological information as is necessary for accurate reconstruction. We consider a variety of one- and two-dimensional reconstructions, including periodic and random arrays of rods, various distribution of disks, Debye random media, and a Fontainebleau sandstone sample. We also use our algorithm to construct heterogeneous media from specified hypothetical correlation functions, including an exponentially damped, oscillating function as well as physically unrealizable ones. copyright 1998 The American Physical Society

  17. Correlation of acid-base properties of polymeric chelate sorbents and pH50 of gallium and indium sorption

    Complexing properties of synthesized polymeric chelate-forming sorbents - substituents of polystyrene-azo-pyrocatechol - are investigated and quantitative correlations between pKOH of functional analytical group and pH50 of chelate formation are determined to investigate regularities of interactions in element - sorbent system. Correlations obtained make it possible to realize special forecast on choice and usage of chelate sorbents for separation and concentrating of gallium and indium microquantities from objects of different nature

  18. Infrared study of some 2-substituted-6-hydroxy-4-pyrimidine carboxylic acids. Correlation with MO-calculations

    Juranic, Ivan O.; BRATISLAV Z. JOVANOVIC; UBAVKA B. MIOC; LJUBINKA J. BOGUNOVIC

    2000-01-01

    The IR spectra of a series of 2-substituted-6-hydroxy-4-pyrimidine carboxylic acids (substituent = OH, SH, CH3, CH3S and NH2) were studied from the aspect of the influence of the subsitutent on the polarizability of some bonds, keto-enol tautomerism and hydrogen bond formation. The spectra were taken using solids due to the low solubility of the acids. Theoretical calculations were done using the MNDO-AM1 semiempirical molecular-orbital method. The stabilities of various tautomers were calcul...

  19. Media Flow

    Kabel, Lars

    2015-01-01

    News and other kinds of journalistic stories, 16-17 hours a day, all year round, on all platforms, also the moderated social media. The key research thesis behind this article is that the continuous and speedy stream of news stories and media content now is becoming the centre of the production...... processes and the value creation in converged multimedia newsrooms. The article identify new methods and discuss editorial challenges in handling media flow....

  20. Media Literacy

    O' Neill, Brian; Hagen, Ingun

    2009-01-01

    Across Europe and beyond, the promotion of media literacy, for children and adults, has acquired an important public urgency. Traditional literacy is seen to be no longer sufficient for participation in today’s society. Citizens need to be media literate, it is claimed, to enable them to cope more effectively with the flood of information in today’s highly mediated societies. As teachers, politicians and policy makers everywhere struggle with this rapid shift in media culture, greater respons...

  1. Potentiation of insulin release in response to amino acid methyl esters correlates to activation of islet glutamate dehydrogenase activity

    Kofod, Hans; Lernmark, A; Hedeskov, C J

    1986-01-01

    Column perifusion of mouse pancreatic islets was used to study the ability of amino acids and their methyl esters to influence insulin release and activate islet glutamate dehydrogenase activity. In the absence of L-glutamine, L-serine and the methyl ester of L-phenylalanine, but neither L-phenyl...

  2. Anticonvulsant action of gamma-irradiated diazepam with correlation to certain brain amino acids and electrocorticogram activity in experimental animals

    The effect of sterilization by gamma irradiation (215 KGy) of diazepam on is anticonvulsant action, on norma and depleted cerebral gamma aminobutyric acid (GABA), on glutamic acid, as well as electrocorticogram activity (ECOG) was determined in the experimental animals. For the evaluation of the anticonvulsant action of either diazepam (D) or irradiated diazepam (ID), pentyl ene tetrazole seizure test, was used and the protective dose 50 (PD50) was determined in adult male mice. GABA, the main central inhibitory transmitter which is implicated in the mechanism of the anticonvulsant action of D and its precursor glutamic acid, were electrophoretically separated and spectrophotometrical evaluated. Moreover, brain electrical activity was recorded using an electroencephalograph apparatus. Although the PD50 of ID as well the effect on normal brain cerebral GABA and glutamic acids did not differ significantly from that of D, yet there was certain variabilities. Thus, the effect of D was about 4 times more potent than the ID on elevating depleted cerebral GABA. Also, electrocorticogram records demonstrated that D produced a slight inhibition while ID induced a decrease in B rhythm with remarkable in the amplitude of ECOG waves. The same pattern of effects were obtained when D or ID were used in combination with INH (250 mg kg-1). 1 tab. 1 fig

  3. Mercury in little brown bat (Myotis lucifugus) maternity colonies and its correlation with freshwater acidity in Nova Scotia, Canada.

    Little, Megan E; Burgess, Neil M; Broders, Hugh G; Campbell, Linda M

    2015-02-17

    Insectivorous little brown bats are exposed to elevated concentrations of mercury (Hg) through their preference for aquatic-based prey. Here we investigated spatial patterns of total Hg (THg) in fur from 10 little brown bat maternity colonies across Nova Scotia, and assessed relationships with the acidity of nearby lakes and rivers. Total Hg concentrations were measured in fur samples from 149 adult female little brown bats. Values showed significant variation among colonies (mean range 3.76-27.38 μg/g, dry weight), and 48% of individuals had Hg concentrations in excess of the 10 μg/g threshold associated with neurochemical changes in Chiroptera conspecifics (n = 26) from Virginia. Average surface water acidity parameters (pH and acid neutralization capacity) within an 8 km radius of each maternity roost showed strong negative associations with average colony fur THg concentrations. This suggests that freshwater acidity in foraging grounds explains much of the variation in average fur THg concentrations in little brown bat colonies. These findings highlight the significant role that water quality may have on Hg bioaccumulation within terrestrial species that feed on aquatic prey. PMID:25591047

  4. Mass Media

    叶全荣

    2006-01-01

    @@ Every day,we are all influenced by the mass media.Although some critics of the media claim that these means of communication are used mainly to control our thinking and get us to buy products that we don't need,the media also contribute to keeping people informed.In other words,while dangers do exist,the benefits of the media far outweigh(超过)the disadvantages.Most of the messages brought to viewers,listeners,and readers are designed either to inform or to entertain,and neither of these goals can be considered dangerous or harmful.

  5. Synergistic solvent extraction investigation of Am (III), Eu (III), Zn(II), and Cs(I), using 2-heptyl-2-methyl-nonanoic acid mixed with different organophosphorus compounds from nitrate media. Vol. 3

    Extraction studies for investigating the effect of mixing 2-heptyl-2-methyl nonanoic acid (HA) with a number of organophosphorus compounds; namely tributyl phosphate (TBP), terphenyl phosphate oxide (TPPO); tri octyl phosphine oxide (TOPO) or bis-2-(ethyl hexyl) phosphoric acid (HDEHP) in benzene on the extraction of trace elements Am(III), Eu(III), Zn(II), and Cs(I) from nitrate media of ionic strength, I=0.1 M were carried out. The effect of adding different organophosphorus compounds to HA was tested to account for the presence or absence of the phenomenon of synergism. It was found that TBP, TPPO, and TOPO causing some antagonistic effects for the elements studied. Extraction enhancement was only observed with bis- (2-ethyl-hexyl) -phosphoric acid (HDEHP) for all the elements investigated. The extraction mechanisms as well as the thermodynamic parameters for the mixed extracted species are discussed. 19 figs

  6. Plasma anandamide and other N-acylethanolamines are correlated with their corresponding free fatty acid levels under both fasting and non-fasting conditions in women

    Verhoeckx Kitty CM

    2010-06-01

    Full Text Available Abstract N-acylethanolamines (NAEs, such as anandamide (AEA, are a group of endogenous lipids derived from a fatty acid linked to ethanolamine and have a wide range of biological activities, including regulation of metabolism and food intake. We hypothesized that i NAE plasma levels are associated with levels of total free fatty acids (FFAs and their precursor fatty acid in fasting and non-fasting conditions and ii moderate alcohol consumption alters non-fasting NAE levels. In a fasting and non-fasting study we sampled blood for measurements of specific NAEs and FFAs. In the fasting study blood was drawn after an overnight fast in 22 postmenopausal women. In the non-fasting study blood was sampled before and frequently after a standardized lunch with beer or alcohol-free beer in 19 premenopausal women. Fasting AEA levels correlated with total FFAs (r = 0.84; p N-acylethanolamines and free fatty acids in blood. The trials are registered at ClinicalTrials.gov numbers: NCT00524550 and NCT00652405.

  7. Percolation in Heterogeneous Media

    This work is a theoretical reflection on the problematic of the modeling of heterogeneous media, that is on the way of their simple representation conserving their characteristic features. Two particular problems are addressed in this thesis. Firstly, we study the transport in porous media, that is in a heterogeneous media which structure is quenched. A pore space is represented in a simple way - a pore is symbolized as a tube of a given length and a given diameter. The fact that the correlations in the distribution of pore sizes are taken into account by a construction of a hierarchical network makes possible the modeling of porous media with a porosity distributed over several length scales. The transport in the hierarchical network shows qualitatively different phenomena from those observed in simpler models. A comparison of numerical results with experimental data shows that the hierarchical network gives a good qualitative representation of the structure of real porous media. Secondly, we study a problem of the transport in a heterogeneous media which structure is evolving during the time. The models where the evolution of the structure is not influenced by the transport are studied in detail. These models present a phase transition of the same nature as that observed on the percolation networks. We propose a new theoretical description of this transition, and we express critical exponents describing the evolution of the conductivity as a function of fundamental exponents of percolation theory. (author)

  8. Fatty acid synthesis in Xylella fastidiosa: correlations between genome studies, 13C NMR data, and molecular models

    Xylella fastidiosa was the first plant pathogen to have its complete genome sequence elucidated. Routine database analyses suggested that two enzymes essential for fatty acid synthesis were missing, one of these is the holo-acyl-carrier-protein synthase. However, here we demonstrate, using 13C NMR spectroscopy, that X. fastidiosa is indeed able to synthesize fatty acids from acetate via an apparently conventional metabolic pathway. We further identify a gene product HetI, an alternative phosphopantetheinyl transferase, which we propose to fill the missing link. Homology modeling of HetI shows conservation of the Coenzyme A binding site suggesting it to be an active enzyme and reveals several interesting structural features when compared with the surfactin synthase-activating enzyme, on which the model was built. These include a simplified topology due to N- and C-terminal deletions and the observation of a novel serine ladder

  9. Up-regulation of the integrin alpha 1/beta 1 in human neuroblastoma cells differentiated by retinoic acid: correlation with increased neurite outgrowth response to laminin.

    Rossino, P; P. Defilippi; Silengo, L; Tarone, G.

    1991-01-01

    Retinoic acid (RA) is known to induce differentiation of neuroblastoma cells in vitro. Here we show that treatment of two human neuroblastoma cell lines, SY5Y and IMR32, with RA resulted in a fivefold increase of the integrin alpha 1/beta 1 expression. The effect was selective because expression of the alpha 3/beta 1 integrin, also present in these cells, was not increased. The up-regulation of the alpha 1/beta 1 differentiated SY5Y cells correlated with increased neurite response to laminin....

  10. The correlation of ECHO findings of right cardiac pathologies with BNP, uric acid, and CRP in OSAS

    ARAZ*, Ömer; UÇAR, Elif YILMAZEL; DEĞİRMENCİ, Hüsnü; PULUR, Didem

    2014-01-01

    Right cardiac pathologies develop in patients with obstructive sleep apnea syndrome (OSAS) and in most patients there are no symptoms in the early stages of right cardiac disorders. We aimed to evaluate a possible relationship between B-type natriuretic peptide (BNP), blood uric acid, C-reactive protein (CRP), and the right cardiac pathologies in patients with OSAS, and the role of these parameters in the management of patients with OSAS. Materials and methods: A total of 98 subjects, 31 (31...

  11. Sensory Description of Cultivars (Coffea Arabica L.) Resistant to Rust and Its Correlation with Caffeine, Trigonelline, and Chlorogenic Acid Compounds

    Larissa de Oliveira Fassio; Marcelo Ribeiro Malta; Gladyston Rodrigues Carvalho; Gilberto Rodrigues Liska; Priscilla Magalhães de Lima; Carlos José Pimenta

    2016-01-01

    Considering the importance of the chemical compounds in Arabica coffee beans in the definition of the drink sensory quality and authentication of coffee regions, the aim of this study was to evaluate, from principal component analysis—PCA—if there is a relation between the caffeine, trigonelline, and chlorogenic acid (5-CQA) content and the sensory attributes of the drink, and in this context, enabling the differentiation of cultivars in two coffee-producing regions of Brazil. We evaluated se...

  12. Correlations between the contents of phytic acid and inorganic phosphorous and downy mildew resistance of corn inbred lines

    Pantipa Na Chiangmai*; Phrutiya Nilprapruck; Warapon Bunkoed; Phakatip Yodmingkhwan; Chokechai Aekatasanawan; Mana Kanjanamaneesathian

    2015-01-01

    Seeds of corn inbred lines collected at the National Corn and Sorghum Research Center (NCSRC), Kasetsart University, were analyzed to determine the contents of phytic acid (PA) and inorganic phosphorous (InP). These 28 and 29 inbred lines were cultivated at the NCSRC (in the 2008 late rainy season and 2009 early rainy season) to evaluate their resistance to corn downy mildew caused by Peronosclerospora sorghi. Results showed that the values of the PA, InP contents and downy mildew...

  13. Print media vs internet media

    Koganuramath, M. M.; Angadi, Mallikarjun

    1999-01-01

    The Information Technology has revolutionised the communication media with the emergence of Internet. This paper describes the pace of change in print media to On-line journalism. The process has began with On-line journalism utilising Internet wherein websites are replacing the print media. Most of the On-line newspapers are free, interactive and archival in nature and it provides users to search the information on newspapers through various access points i.e. by contributors, title, and dat...

  14. Mixed Media

    Peterson, Erin

    2010-01-01

    While institutions do not often have a hook as compelling as an eagerly awaited movie, great content is critical for media relations success--and coupling it with the right distribution channel can ensure the story finds the right audience. Even better, retooling it for several media platforms can extend the life and reach of a story. The changes…

  15. Media darling

    Chalmers, Matthew

    2008-01-01

    He is the media-friendly face of particle physics, appearing on countless TV and radio shows in the run-up to the opening of CERN's Large Hadron Collider. Matthew Chalmers discovers how Brian Cox finds the time to be both a physicist and a media personality. (2 pages)

  16. Biorelevant dissolution media

    Ilardia-Arana, David; Kristensen, Henning G; Müllertz, Anette

    2006-01-01

    concentration. Dilution of the two- and four component media caused enlargement of the mixed micelles and formation of vesicles. The solubility of estradiol in the buffer solution was increased with addition of the amphiphiles. A good correlation (R(2) = 0.987) was found between estradiol solubility and mass......Biorelevant dissolution media containing bile salt and lecithin at concentrations appropriate for fed and fasted state are useful when testing oral solid formulations of poorly water-soluble drugs. Dilution of amphiphile solutions affects the aggregation state of the amphiphiles because bile salt...

  17. Correlations between periparturient serum concentrations of non-esterified fatty acids, beta-hydroxybutyric acid, bilirubin, and urea and the occurrence of clinical and subclinical postpartum bovine endometritis

    Tenhagen Bernd-Alois

    2010-10-01

    Full Text Available Abstract Background Postpartum endometritis in cattle is a multifactorial disease with high economic impact. Both, clinical endometritis (CE and subclinical endometritis (SCE result in decreased reproductive performance. Results from in vitro studies led to the implication that non-esterified fatty acids (NEFA, beta-hydroxybutyric acid (BHBA, bilirubin, and urea could be used as predictors for endometritis in veterinary practice. In this field study, we set out to establish optimal predictor cut points of these metabolic parameters for the detection of CE and SCE. Serum samples were collected one week prior to parturition (wk -1, in the first week postpartum (wk +1 and between 28 and 35 days postpartum (wk +5 from 209 Holstein-Friesian cows. At wk +5, all cows were examined for signs of CE and SCE. Results Higher concentrations of urea at wk +1 were associated with increased odds of CE (OR = 1.7, P = 0.04 in primiparous (PP cows. A predictor cut point of 3.9 mmol/L (sensitivity: 61%, specificity: 70% was determined. In multiparous (MP cows, the logistic regression model revealed that higher concentrations of NEFA at wk -1 were associated with increased odds of CE and SCE (healthy vs. CE: OR = 9.1, P = 0.05; healthy vs. SCE: OR = 12.1, P = 0.04. A predictor cut point of 0.3 mmol/L (sensitivity: 38%, specificity: 87% and sensitivity: 35%, specificity: 89%, respectively was determined. Increasing concentrations of urea at wk +5 were associated with decreased odds of CE (healthy vs. CE: OR = 0.6, P = 0.01; SCE vs. CE: OR = 0.5, P = 0.03. A predictor cut point of 3.8 mmol/L (sensitivity: 52%, specificity: 81% was determined. For BHBA and bilirubin relationships with CE or SCE were not detected. Conclusions The corresponding combinations of sensitivity and specificity of the determined predictor cut points were not satisfactory for practical use. Thus, the analysed parameters, i.e. NEFA, BHBA, bilirubin, and urea, at the chosen time points, i.e. at wk

  18. Determination and correlation of the solubility of four Brønsted-acidic ionic liquids based on benzothiazolium cations in six alcohols

    Highlights: • Solubility of four acidic benzothiazolium cations-based ILs was measured. • The solubilities vary with the polarity of the solvent. • The solubility of some ILs is with “temperature-sensitive” property. • The measured solubilities were correlated by Apelblat model and λh model. • The dissolution enthalpy and entropy of ILs were calculated using the van’t Hoff equation. - Abstract: Solubilities of four acidic ionic liquids based on benzothiazolium cations in six alcohols (methanol, ethanol, 1-propanol, 2-propanol, 1-butanol and 2-methyl-1-propanol) from at temperatures from (253 to 384) K were determined using a static equilibrium method under atmospheric pressure. The modified Apelblat equation and λh equation were employed to correlate the experimental data with good agreement. The solubilities of ILs increase with increasing temperature. It is interesting to find that the solubility of some ILs in alcohols are with “temperature-sensitive” properties. The solubility is related with the polarity and molecular structures of the solvent, as well as the strength of hydrogen bonding between alcohols and anionic groups of ILs. The dissolution enthalpy and entropy of ILs were calculated by the van’t Hoff equation. This study provides useful information for further research and application of the ionic liquids

  19. Circulating Endothelial Microparticles and Correlation of Serum 1,25-Dihydroxyvitamin D with Adiponectin, Nonesterified Fatty Acids, and Glycerol from Middle-Aged Men in China

    Wan, Zhongxiao; Yu, Lugang; Cheng, Jinbo; Zhang, Zengli; Xu, Baohui; Pang, Xing; Zhou, Hui; Lei, Ting

    2016-01-01

    The aim of the present study is (1) to determine the correlation between circulating 1,25-dihydroxyvitamin D [25(OH)D] and adiponectin, nonesterified fatty acids (NEFAs), and glycerol and (2) to determine the alterations in circulating endothelial microparticles (EMPs) in Chinese male subjects with increased body mass index (BMI). A total of 45 male adults were enrolled with varied BMI [i.e., lean, overweight (OW), and obese (OB), N = 15 per group]. Blood samples were collected under overnight fasting condition, and plasma was isolated for the measurement of endothelial microparticles (EMPs), total and high-molecular weight (HMW) adiponectin, 25(OH)D, nonesterified fatty acids (NEFAs), and glycerol. Circulating 25(OH)D levels were inversely associated with total adiponectin, NEFA, and glycerol levels. There is no difference for CD62E+ or CD31+/CD42b− EMPs among 3 groups. In Chinese male adults with varied BMI, an inverse correlation existed between 25(OH)D levels and total adiponectin, NEFA, and glycerol levels; and there is no significant difference for CD62E+ or CD31+/CD42b− EMPs among lean, overweight, and obese subjects. PMID:27314039

  20. Endocannabinoid and cannabinoid-like fatty acid amide levels correlate with pain-related symptoms in patients with IBS-D and IBS-C: a pilot study.

    Jakub Fichna

    Full Text Available AIMS: Irritable bowel syndrome (IBS is a functional gastrointestinal (GI disorder, associated with alterations of bowel function, abdominal pain and other symptoms related to the GI tract. Recently the endogenous cannabinoid system (ECS was shown to be involved in the physiological and pathophysiological control of the GI function. The aim of this pilot study was to investigate whether IBS defining symptoms correlate with changes in endocannabinoids or cannabinoid like fatty acid levels in IBS patients. METHODS: AEA, 2-AG, OEA and PEA plasma levels were determined in diarrhoea-predominant (IBS-D and constipation-predominant (IBS-C patients and were compared to healthy subjects, following the establishment of correlations between biolipid contents and disease symptoms. FAAH mRNA levels were evaluated in colonic biopsies from IBS-D and IBS-C patients and matched controls. RESULTS: Patients with IBS-D had higher levels of 2AG and lower levels of OEA and PEA. In contrast, patients with IBS-C had higher levels of OEA. Multivariate analysis found that lower PEA levels are associated with cramping abdominal pain. FAAH mRNA levels were lower in patients with IBS-C. CONCLUSION: IBS subtypes and their symptoms show distinct alterations of endocannabinoid and endocannabinoid-like fatty acid levels. These changes may partially result from reduced FAAH expression. The here reported changes support the notion that the ECS is involved in the pathophysiology of IBS and the development of IBS symptoms.

  1. Influence of acid tolerance responses on survival, growth, and thermal cross-protection of Escherichia coli O157:H7 in acidified media and fruit juices.

    Ryu, J H; Beuchat, L R

    1998-12-22

    A study was done to determine survival and growth characteristics of acid-adapted, acid-shocked, and control cells of Escherichia coli O157:H7 inoculated into tryptic soy broth (TSB) acidified with organic acids and three commercial brands of apple cider and orange juice. The three types of cells behaved similarly in TSB acidified with acetic acid; however, in TSB (pH 3.9) acidified with lactic acid, acid-adapted cells were more tolerant than acid-shocked cells which, in turn, were more tolerant than control cells. The ability of the three types of cells to grow after inoculation into acidified TSB, then plated on tryptic soy agar containing sodium chloride was determined. Tolerance of acid-adapted cells and, less markedly, acid-shocked cells to sodium chloride was diminished, compared to control cells. The pathogen showed extraordinary tolerance to the low pH of apple cider and orange juice held at 5 or 25 degrees C for up to 42 days. Growth occurred in one brand of apple cider (pH 3.98) incubated at 25 degrees C. Regardless of test parameters, there was no indication that cell types differed in tolerance to the acidic environment in apple cider or orange juice. Survival of control, acid-adapted, and acid-shocked cells heated in apple cider and orange juice was studied. Within each apple cider or orange juice, D(52 degrees C)-values of acid-adapted cells were considerably higher than those of acid-shocked or control cells, which indicates that heat tolerance can be substantially enhanced by acid adaptation compared to acid shock. PMID:9926995

  2. Correlation between aggregation and extracting properties in solvent extraction systems: extraction of actinides (III) and lanthanides (III) by a malonamide in non acidic media

    The organic phases of the DIAMEX (Diamide Extraction) process, allowing the co-extraction of actinides(III) and lanthanides(III) from high level radioactive wastes using a malonamide extractant molecule (DMDOHEMA) diluted in alkanes, are investigated. The aim of this study is to establish a link between different structures/organizations of diamide extractants and their extracting properties towards An(III) and Ln(III) cations. It is demonstrated that diamide, which are amphiphilic molecules, are organized in different structures (monomers, reverse micelles, lamellar phases..). This study deals with the effect of the composition of the extracting system on the extracting and aggregation properties of the DMDOHEMA solutions. The effects of the extractant (DMDOHEMA diluted in n-heptane) and metal concentrations (for a given extractant concentration) from a LiNO3 aqueous phase are investigated at two scales: at the supra-molecular scale by characterizing the aggregation by vapor-pressure osmometry (VPO) and small angle neutron and X-ray scattering (SANS and SAXS) experiments, and at the molecular scale by quantifying the extracted solutes (metal nitrate and water) and by determining the stoichiometries of the extracted complexes by electro-spray mass spectrometry (ESI-MS). The extraction equilibria can then be modeled by two approaches: a classical approach in solvent extraction based on mass action laws to determine extraction equilibria and their associated thermodynamic constants, and a physical chemical approach which consists in considering the extracted ions as adsorbed on a specific available surface of the extractant molecule. Thus, the extraction equilibrium can be considered as a sum of Langmuir isotherms corresponding to the different states of aggregation. The resulting constants are representative of both extraction efficiency and organic phase structure. (authors)

  3. Correlation between aggregation and extracting properties in solvent extraction systems: extraction of actinides (III) and lanthanides (III) by a malonamide in non acidic media

    Meridiano, Y.; Berthon, L.; Lagrave, S.; Crozes, X.; Sorel, C.; Testard, F.; Zemb, T. [CEA Marcoule, DEN/DRCP/SCPS/LCSE, 30207Bagnols sur Ceze (France)

    2008-07-01

    The organic phases of the DIAMEX (Diamide Extraction) process, allowing the co-extraction of actinides(III) and lanthanides(III) from high level radioactive wastes using a malonamide extractant molecule (DMDOHEMA) diluted in alkanes, are investigated. The aim of this study is to establish a link between different structures/organizations of diamide extractants and their extracting properties towards An(III) and Ln(III) cations. It is demonstrated that diamide, which are amphiphilic molecules, are organized in different structures (monomers, reverse micelles, lamellar phases..). This study deals with the effect of the composition of the extracting system on the extracting and aggregation properties of the DMDOHEMA solutions. The effects of the extractant (DMDOHEMA diluted in n-heptane) and metal concentrations (for a given extractant concentration) from a LiNO{sub 3} aqueous phase are investigated at two scales: at the supra-molecular scale by characterizing the aggregation by vapor-pressure osmometry (VPO) and small angle neutron and X-ray scattering (SANS and SAXS) experiments, and at the molecular scale by quantifying the extracted solutes (metal nitrate and water) and by determining the stoichiometries of the extracted complexes by electro-spray mass spectrometry (ESI-MS). The extraction equilibria can then be modeled by two approaches: a classical approach in solvent extraction based on mass action laws to determine extraction equilibria and their associated thermodynamic constants, and a physical chemical approach which consists in considering the extracted ions as adsorbed on a specific available surface of the extractant molecule. Thus, the extraction equilibrium can be considered as a sum of Langmuir isotherms corresponding to the different states of aggregation. The resulting constants are representative of both extraction efficiency and organic phase structure. (authors)

  4. Social media

    Sova, Ondřej

    2012-01-01

    This thesis deals with social media and is trying to characterize them with focus on their development which led to the creation of social networks. The history of the internet is very short, but its development was giant, and only few people can imagine the world without it. Social media grew in parallel to the internet, so they are its integral part from the beginning. Social media were slowly replacing press, because they gave us a new dimension in the form of immediate feedback. They also...

  5. Decreased mental time travel to the past correlates with default-mode network disintegration under lysergic acid diethylamide.

    Speth, Jana; Speth, Clemens; Kaelen, Mendel; Schloerscheidt, Astrid M; Feilding, Amanda; Nutt, David J; Carhart-Harris, Robin L

    2016-04-01

    This paper reports on the effects of LSD on mental time travel during spontaneous mentation. Twenty healthy volunteers participated in a placebo-controlled crossover study, incorporating intravenous administration of LSD (75 μg) and placebo (saline) prior to functional magnetic resonance imaging (fMRI). Six independent, blind judges analysed mentation reports acquired during structured interviews performed shortly after the functional magnetic resonance imaging (fMRI) scans (approximately 2.5 h post-administration). Within each report, specific linguistic references to mental spaces for the past, present and future were identified. Results revealed significantly fewer mental spaces for the past under LSD and this effect correlated with the general intensity of the drug's subjective effects. No differences in the number of mental spaces for the present or future were observed. Consistent with the previously proposed role of the default-mode network (DMN) in autobiographical memory recollection and ruminative thought, decreased resting-state functional connectivity (RSFC) within the DMN correlated with decreased mental time travel to the past. These results are discussed in relation to potential therapeutic applications of LSD and related psychedelics, e.g. in the treatment of depression, for which excessive reflection on one's past, likely mediated by DMN functioning, is symptomatic. PMID:26979587

  6. Combined use of Wallerstein and Zygosaccharomyces bailii modified differential media to isolate yeasts for the controlled reduction of volatile acidity of grape musts and wines

    Alice, Vilela; Carla, Amaral; Dorit, Schuller; Arlete, Menes-Faia; Manuela, Côrte-Real

    2015-01-01

    The level of acetic acid, the main component of volatile acidity, is critical for wine quality. Winemakers have been using a refermentation process to lower the concentration of acetic acid of wines with high volatile acidity, which consists in mixing the acidic wine with freshly crushed grapes or marcs in a proportion of no more than 20-30% (v/v). Though this process implies low costs it harbors the risk of unexpected and detrimental effects on refermented wines. Thus, one challenge to find ...

  7. Community Media: Muting the Democratic Media Discourse?

    Carpentier, N.; Lie, R.; Servaes, J.

    2003-01-01

    Focuses on the concept of community media. Components that construct the identity of community media; Multi-theoretical approaches for analysis of community media; Definition of community media based on the concept of alternative media; Link between community media and civil society; Problems faced

  8. From Augmentation Media to Meme Media.

    Tanaka, Yuzuru

    Computers as meta media are now evolving from augmentation media vehicles to meme media vehicles. While an augmentation media system provides a seamlessly integrated environment of various tools and documents, meme media system provides further functions to edit and distribute tools and documents. Documents and tools on meme media can easily…

  9. Media violence.

    Willis, E; Strasburger, V C

    1998-04-01

    American media are the most violent in the world, and American society is now paying a high price in terms of real life violence. Research has confirmed that mass media violence contributes to aggressive behavior, fear, and desensitization of violence. Television, movies, music videos, computer/video games are pervasive media and represent important influences on children and adolescents. Portraying rewards and punishments and showing the consequences of violence are probably the two most essential contextual factors for viewers as they interpret the meaning of what they are viewing on television. Public health efforts have emphasized public education, media literacy campaign for children and parents, and an increased use of technology to prevent access to certain harmful medial materials. PMID:9568012

  10. Social Media

    Weller, Katrin; Meckel, Martin Sebastian; Stahl, Matthias

    2013-01-01

    Anlässlich der 10. Wissenschaftlichen Tagung „Soziale Medien“ am 27. und 28. Juni 2013 im Statistischen Bundesamt in Wiesbaden und in Fortsetzung des 2010 erschienenen Recherche Spezial Web 2.0 – Alle machen mit! werden in dieser Ausgabe in sechs Kapiteln Nachweise zu Veröffentlichungen und Forschungsprojekte der letzten drei Jahre zusammengestellt, die sich mit der Rolle von Social Media in verschiedenen Nutzungskontexten befassen. Social-Media-Dienste sind mittlerweile fester Bestandtei...

  11. Transport of ARS-labeled hydroxyapatite nanoparticles in saturated granular media is influenced by surface charge variability even in the presence of humic acid

    Hydroxyapatite nanoparticles (nHAP) are increasingly being used to remediate soils and water polluted by metals and radionuclides. The transport and retention of Alizarin red S (ARS)-labeled nHAP in water-saturated granular media were investigated. Experiments were conducted over a range of ionic ...

  12. 5-(2-Cyclohexylideneethyl)-5-ethyl barbituric acid (CHEB): correlation of hypnotic and convulsant properties with alterations of synaptosomal 45Ca2+ influx

    Male ICR mice were given either 5-(2-cyclohexylideneethyl)-5-ethyl barbituric acid (CHEB) alone or CHEB after a 1 h pretreatment with phenobarbital CHEB alone produced excitatory behavior but not convulsive seizures. Higher doses produced convulsive seizures resulting in death. Pretreatment with phenobarbital prevented seizure activity. In vitro, CHEB significantly inhibited 'fast-phase' K+-stimulated 45Ca2+ uptake into cerebrocortical synaptosomes. CHEB also significantly increased basal 45Ca2+ uptake. The addition of CHEB or pentobarbital to striatal synaptosomes inhibited 'fast-phase' K+-stimulated 45Ca2+ uptake and endogenous dopamine release. CHEB, but not pentobarbital, produced a time- and dose-dependent increase in the resulting release of endogenous dopamine from striatal synaptosomes. The results of this study show that CHEB possesses hypnotic activity if its lethal convulsant actions are blocked. The hypnotic actions of CHEB appear to correlate with inhibition of voltage-dependent calcium channels in brain synaptosomes. (Auth.)

  13. Yuanhuapine-induced intestinal and hepatotoxicity were correlated with disturbance of amino acids, lipids, carbohydrate metabolism and gut microflora function: A rat urine metabonomic study.

    Chen, Yanyan; Duan, Jin-Ao; Guo, Jianming; Shang, Erxin; Tang, Yuping; Qian, Yefei; Tao, Weiwei; Liu, Pei

    2016-07-15

    This research was designed to study metabonomic characteristics of the toxicity induced by yuanhuapine, a major bioactive diterpenoid in a well-known traditional Chinese medicine-Genkwa Flos. General observation, blood biochemistry and histopathological examination were used to reflect yuanhuapine-induced toxicity. Urine samples from rats in control and yuanhuapine treated rats were analyzed by ultra-performance liquid chromatography tandem quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF/MS). Pattern recognition methods including principal components analysis (PCA), partial least-squared discriminant analysis (PLS-DA), orthogonal partial least-squared discriminant analysis (OPLS-DA) and computational system analysis were integrated to obtain comprehensive metabonomic profiling and pathways of the biological data sets. The results suggested that yuanhuapine could induce intestinal and liver damage. And 14 endogenous metabolites as biomarkers related to the amino acids metabolism, lipids metabolism, carbohydrate metabolism and gut microflora were significantly changed in the urine of yuanhuapine treated rats, which were firstly constructed the metabolomic feature profiling and metabolite interaction network of yuanhuapine-induced injury using pattern recognition methods and Ingenuity Pathway Analysis (IPA) approach. The present study showed that yuanhuapine-induced intestinal and hepatic toxicity were correlated with disturbance of amino acids metabolism, lipids metabolism, carbohydrate metabolism and gut microflora. PMID:26341729

  14. Efficient, Validated Method for Detection of Mycobacterial Growth in Liquid Culture Media by Use of Bead Beating, Magnetic-Particle-Based Nucleic Acid Isolation, and Quantitative PCR

    Plain, Karren M.; Waldron, Anna M.; Begg, Douglas J.; de Silva, Kumudika; Purdie, Auriol C.; Whittington, Richard J.

    2015-01-01

    Pathogenic mycobacteria are difficult to culture, requiring specialized media and a long incubation time, and have complex and exceedingly robust cell walls. Mycobacterium avium subsp. paratuberculosis (MAP), the causative agent of Johne's disease, a chronic wasting disease of ruminants, is a typical example. Culture of MAP from the feces and intestinal tissues is a commonly used test for confirmation of infection. Liquid medium offers greater sensitivity than solid medium for detection of MA...

  15. Correlation between precipitation and geographical location of the δ2H values of the fatty acids in milk and bulk milk powder

    Ehtesham, E.; Baisden, W. T.; Keller, E. D.; Hayman, A. R.; Van Hale, R.; Frew, R. D.

    2013-06-01

    Hydrogen isotope ratios (δ2H) have become a tool for food traceability and authentication of agricultural products. The principle is that the isotopic composition of the produce is influenced by environmental and biological factors and hence exhibits a spatial differentiation of δ2H. This study investigates the variation in δ2H values of New Zealand milk, both in the bulk powder and individual fatty acids extracted from milk samples from dairy factories across New Zealand. Multivariate statistical analyses were used to test for relationships between δ2H of bulk milk powder, milk fatty acid and geographical location. Milk powder samples from different regions of New Zealand were found to exhibit patterns in isotopic composition similar to the corresponding regional precipitation associated with their origin. A model of δ2H in precipitation was developed based on measurements between 2007 and 2010 at 51 stations across New Zealand (Frew and Van Hale, 2011). The model uses multiple linear regressions to predict daily δ2H from 2 geographic and 5 rain-weighted climate variables from the 5 × 5 km New Zealand Virtual Climate Station Network (VCSN). To approximate collection radius for a drying facility the modelled values were aggregated within a 50 km radius of each dairy factory and compared to observed δ2H values of precipitation and bulk milk powder. Daily δ2H predictions for the period from August to December for the area surrounding the sample collection sites were highly correlated with the δ2H values of bulk milk powder. Therefore the δ2H value of milk fatty acids demonstrates promise as a tool for determining the provenance of milk powders and products where milk powder is an ingredient. Separation of milk powder origin to geographic sub-regions within New Zealand was achieved. Hydrogen isotope measurements could be used to complement traditional tracking systems in verifying point of origin.

  16. Study of the role of serum folic acid in atopic dermatitis: A correlation with serum IgE and disease severity

    Maha A Shaheen

    2011-01-01

    Full Text Available Background : Most atopic dermatitis (AD patients have elevated serum immunoglobulin E (IgE. Impaired folic acid (FA metabolism was found to reduce the intracellular methyl donor pool, associated with a higher prevalence of atopy. Aim : To assess serum IgE and FA in AD patients and to correlate their levels with the disease severity, and with each other. Materials and Methods : Twenty patients with AD were assessed for serum FA and IgE, compared with 20 age- and sex-matched controls. Patients were classified into three groups (mild, moderate, and severe AD based on clinical severity according to Nottingham index. In both patients and controls, serum IgE was measured using Enzyme-linked immunosorbent assay technique and serum FA was measured using Microparticle Enzyme Immunoassay technique. Results : Serum FA levels were lower in AD patients compared with controls, but the difference was not statistically significant. FA levels did not show statistically significant difference among disease severity groups and did not correlate with serum IgE levels. On the other hand, serum IgE levels were significantly elevated in AD patients compared with controls, and among AD patients, its levels were significantly elevated in severe AD compared with mild and moderate disease. Conclusion : Serum IgE is useful in assessment of AD severity and activity. FA contribution to AD needs further investigations.

  17. Death in media

    Pavićević Aleksandra

    2010-01-01

    Full Text Available This paper discusses the role of media in a construction of public image speech and presentation of death. The main research questions could be posed as follows: does the media discourse confirm a thesis about modern society as the one which intensely avoids encounter with Death, or does it defy it? Frequent images or hints of death in visual media in films informative and entertainment programs-suggest certain changes related to this issue in the past few decades. This analysis focuses on printed media hence the paper assesses numerous issues of the daily journal Politika from 1963, 1972, 1973, 1979, 1985, 1991, 1995, 1999, 2007 and 2008, as well as some other daily journals after 2000. The analysis confirms a strong connection between the current political systems and ideology and speech about death. In addition, it reveals a political usage of this event but also speaks up about cultural and historical models, underlying all other constructions. During the 1960's and 1970's, the presentations, including the speech about death relied on the traditional understandings about inevitability of death and dying, and alternatively on atheistic beliefs related to the progress and wellbeing of the society. In this particular discourse, death was present to a limited degree, serving primarily to glorify socialist order. The end of the 1970's witnessed an increase in the glorification of the death, correlated with the decrease of the dominant political ideology. On the other hand, the 1990's brought about more presence of the national and religious symbolism and glorification of the dead as heroes. After 2000, mercantilism is evident throughout the media. All of the media broadcast drastic images of death and dead, thus providing an answer to the posed question at the beginning of this paper about the relationship of the modern society towards death but nevertheless, this still leaves out many implicit consequences and possible meanings.

  18. Use of social media by airports

    Nigel Halpern

    2012-10-01

    Full Text Available This article investigates the use of social media by airports using content analysis of 1,559 airport websites. One-fifth of airports use at least one type of social media. There is a greater use of social media by airports in North America and Europe, by larger airports, and by airports that are owned and operated by private interests. Demand for social media is greater at airports in North America and Europe, and at larger airports. Findings from 183 airport Twitter accounts demonstrate a positive correlation between the extent to which airports are active users of social media and the number of followers that they have.

  19. Media Training

    CERN. Geneva

    2009-01-01

    With the LHC starting up soon, the world's media are again turning their attention to CERN. We're all likely to be called upon to explain what is happening at CERN to media, friends and neighbours. The seminar will be given by BBC television news journalists Liz Pike and Nadia Marchant, and will deal with the kind of questions we're likely to be confronted with through the restart period. The training is open for everybody. Make sure you arrive early enough to get a seat - there are only 200 seats in the Globe. The session will also be webcast: http://webcast.cern.ch/

  20. Seasonal and spatial variability of the OM/OC mass ratios and high regional correlation between oxalic acid and zinc in Chinese urban organic aerosols

    L. Xing

    2013-04-01

    Full Text Available We calculated the organic matter to organic carbon mass ratios (OM/OC mass ratios in PM2.5 collected from 14 Chinese cities during summer and winter of 2003 and analyzed the causes for their seasonal and spatial variability. The OM/OC mass ratios were calculated two ways. Using a mass balance method, the calculated OM/OC mass ratios averaged 1.92 ± 0.39 year-round, with no significant seasonal or spatial variation. The second calculation was based on chemical species analyses of the organic compounds extracted from the PM2.5 samples using dichloromethane/methanol and water. The calculated OM/OC mass ratio in summer was relatively high (1.75 ± 0.13 and spatially-invariant due to vigorous photochemistry and secondary organic aerosol (OA production throughout the country. The calculated OM/OC mass ratio in winter (1.59 ± 0.18 was significantly lower than that in summer, with lower values in northern cities (1.51 ± 0.07 than in southern cities (1.65 ± 0.15. This likely reflects the wider usage of coal for heating purposes in northern China in winter, in contrast to the larger contributions from biofuel and biomass burning in southern China in winter. On average, organic matter constituted 36% and 34% of Chinese urban PM2.5 mass in summer and winter, respectively. We report, for the first time, a high regional correlation between Zn and oxalic acid in Chinese urban aerosols in summer. This is consistent with the formation of stable Zn oxalate complex in the aerosol phase previously proposed by Furukawa and Takahashi (2011. We found that many other dicarboxylic acids were also highly correlated with Zn in the summer Chinese urban aerosol samples, suggesting that they may also form stable organic complexes with Zn. Such formation may have profound implications for the atmospheric abundance and hygroscopic properties of aerosol dicarboxylic acids.

  1. Increased Levels of Human Carotid Lesion Linoleic Acid Hydroperoxide in Symptomatic and Asymptomatic Patients Is Inversely Correlated with Serum HDL and Paraoxonase 1 Activity

    Elad Cohen

    2012-01-01

    Full Text Available Human carotid plaque components interact directly with circulating blood elements and thus they might affect each other. We determined plaque paraoxonase1 (PON1 hydrolytic-catalytic activity and compared plaque and blood levels of lipids, HDL, PON1, and HbA1c, as well as plaque-oxidized lipids in symptomatic and asymptomatic patients. Human carotid plaques were obtained from symptomatic and asymptomatic patients undergoing routine endarterectomy, and the lesions were ground and extracted for PON activity and lipid content determinations. Plaque PONs preserved paraoxonase, arylesterase, and lactonase activities. The PON1-specific inhibitor 2-hydroxyquinoline almost completely inhibited paraoxonase and lactonase activities, while only moderately inhibiting arylesterase activity. Oxysterol and triglyceride levels in plaques from symptomatic and asymptomatic patients did not differ significantly, but plaques from symptomatic patients had significantly higher (135% linoleic acid hydroperoxide (LA-13OOH levels. Their serum PON1 activity, cholesterol and triglyceride levels did not differ significantly, but symptomatic patients had significantly lower (28% serum HDL levels and higher (18% HbA1c levels. Thus LA-13OOH, a major atherogenic plaque element, showed significant negative correlations with serum PON1 activity and HDL levels, and a positive correlation with the prodiabetic atherogenic HbA1c. Plaque PON1 retains its activity and may decrease plaque atherogenicity by reducing specific oxidized lipids (e.g., LA-13OOH. The inverse correlation between plaque LA-13OOH level and serum HDL level and PON1 activity suggests a role for serum HDL and PON1 in LA-13OOH accumulation.

  2. Streaming Media

    Pulley, John

    2009-01-01

    At a time when the evolutionary pace of new media resembles the real-time mutation of certain microorganisms, the age-old question of how best to connect with constituents can seem impossibly complex--even for an elite institution plugged into the motherboard of Silicon Valley. Identifying the most effective vehicle for reaching a particular…

  3. Media democracy

    Pels, D.

    2008-01-01

    The present article compendiously presents the interlinked and abruptly developing processes of media democracy and political matters’ personalization. The writer expressly opts for these processes which can radically rejuvenate communication and trust among citizens and politicians and therefore reinforce, up to a certain extend, modern democracy’s function itself.

  4. One-pot, three-component synthesis of a library of spirooxindole-pyrimidines catalyzed by magnetic nanoparticle supported dodecyl benzenesulfonic acid in aqueous media.

    Deng, Jia; Mo, Li-Ping; Zhao, Fei-Yang; Zhang, Zhan-Hui; Liu, Shou-Xin

    2012-05-14

    Dodecyl benzenesulfonic acid functionalized silica-coated magnetic nanoparticles (γ-Fe2O3@SiO2-DDBSA) were readily prepared and identified as an efficient catalyst for the synthesis of a library of spirooxindole-pyrimidine derivatives by three-component condensation reaction of barbituric acids, isatins and cyclohexane-1,3-diones. The aqueous reaction medium, easy recovery of the catalyst using an external magnet, and high yields make the protocol sustainable and economic. PMID:22533528

  5. RESEARCH REGARDING THE DYNAMICS OF SOME BIOCHEMICAL MARKERS OF OXIDATIVE STRESS AT MONILINIA LAXA (ADRH. & RUHL. HONEY CULTIVATED ON DIFFERENT AMINO ACIDS ENRICHED MEDIA

    Elena Ciornea

    2011-11-01

    Full Text Available Antioxidants that make up the defense for Ascomycetes still arouses a major interest because of their hypothetical role as virulence and aggression factors and also as the enzymes that play a key role in cellular defense against ROS produced during microbial metabolic activity. A study of catalase and peroxidase activity dynamics of the species Monilinia laxa (Aderh & Ruhl. Honey cultivated in vitro on medium supplemented with different amino acids was conducted in order to know the biology of the fungi responsible for the appearance of brown rot at various species of stone fruits. We used for this purpose the Leonian medium (in the formula changed by Bonnar, in each variant being added 0, 125 mg of the following amino acids: alanine, glutamic acid, asparagine, aspartic acid, cystine, cysteine, phenylalanine, histidine, valine, lysine, serine, methionine and leucine. We also used a control variant, without amino acids, in final resulting 14 working versions. To determine the catalase activity Sinha method was used, to monitor the peroxidase activity we used Möller method and the experimental measurements carried out at two intervals, were made both of fungus mycelium and culture fluid. We found notable differences in the activity of two enzymes, microbial culture induced both by the age of the culture medium and the type of amino acid introduced in it.

  6. RESEARCH REGARDING THE DYNAMICS OF SOME BIOCHEMICAL MARKERS OF OXIDATIVE STRESS AT MONILINIA LAXA (ADRH. & RUHL. HONEY CULTIVATED ON DIFFERENT AMINO ACIDS ENRICHED MEDIA

    Elena Ciornea

    2010-09-01

    Full Text Available Antioxidants that make up the defense for Ascomycetes still arouses a major interest because of their hypothetical role as virulence and aggression factors and also as the enzymes that play a key role in cellular defense against ROS produced during microbial metabolic activity. A study of catalase and peroxidase activity dynamics of the species Monilinia laxa (Aderh & Ruhl. Honey cultivated in vitro on medium supplemented with different amino acids was conducted in order to know the biology of the fungi responsible for the appearance of brown rot at various species of stone fruits. We used for this purpose the Leonian medium (in the formula changed by Bonnar, in each variant being added 0, 125 mg of the following amino acids: alanine, glutamic acid, asparagine, aspartic acid, cystine, cysteine, phenylalanine, histidine, valine, lysine, serine, methionine and leucine. We also used a control variant, without amino acids, in final resulting 14 working versions. To determine the catalase activity Sinha method was used, to monitor the peroxidase activity we used Möller method and the experimental measurements carried out at two intervals, were made both of fungus mycelium and culture fluid. We found notable differences in the activity of two enzymes, microbial culture induced both by the age of the culture medium and the type of amino acid introduced in it.

  7. Prediction of individual milk proteins including free amino acids in bovine milk using mid-infrared spectroscopy and their correlations with milk processing characteristics.

    McDermott, A; Visentin, G; De Marchi, M; Berry, D P; Fenelon, M A; O'Connor, P M; Kenny, O A; McParland, S

    2016-04-01

    The aim of this study was to evaluate the effectiveness of mid-infrared spectroscopy in predicting milk protein and free amino acid (FAA) composition in bovine milk. Milk samples were collected from 7 Irish research herds and represented cows from a range of breeds, parities, and stages of lactation. Mid-infrared spectral data in the range of 900 to 5,000cm(-1) were available for 730milk samples; gold standard methods were used to quantify individual protein fractions and FAA of these samples with a view to predicting these gold standard protein fractions and FAA levels with available mid-infrared spectroscopy data. Separate prediction equations were developed for each trait using partial least squares regression; accuracy of prediction was assessed using both cross validation on a calibration data set (n=400 to 591 samples) and external validation on an independent data set (n=143 to 294 samples). The accuracy of prediction in external validation was the same irrespective of whether undertaken on the entire external validation data set or just within the Holstein-Friesian breed. The strongest coefficient of correlation obtained for protein fractions in external validation was 0.74, 0.69, and 0.67 for total casein, total β-lactoglobulin, and β-casein, respectively. Total proteins (i.e., total casein, total whey, and total lactoglobulin) were predicted with greater accuracy then their respective component traits; prediction accuracy using the infrared spectrum was superior to prediction using just milk protein concentration. Weak to moderate prediction accuracies were observed for FAA. The greatest coefficient of correlation in both cross validation and external validation was for Gly (0.75), indicating a moderate accuracy of prediction. Overall, the FAA prediction models overpredicted the gold standard values. Near-unity correlations existed between total casein and β-casein irrespective of whether the traits were based on the gold standard (0.92) or mid

  8. Short communication: concentrations of nonesterified fatty acids and β-hydroxybutyrate in dairy cows are not well correlated during the transition period.

    McCarthy, M M; Mann, S; Nydam, D V; Overton, T R; McArt, J A A

    2015-09-01

    The objective was to use longitudinal data of blood nonesterified fatty acids (NEFA) and β-hydroxybutyrate (BHBA) concentrations to describe the relationship between NEFA and BHBA in dairy cows during the periparturient period. Blood NEFA and BHBA concentration data collected from d 21 prepartum to 21 postpartum for 269 multiparous Holstein cows were selected from 4 different studies carried out within our research groups. Overall, NEFA concentrations were increased beginning near parturition with a relatively steady elevation of NEFA through d 9, after which concentrations gradually decreased. Prepartum BHBA concentrations began to increase beginning several days before parturition, continued to increase during the first week after parturition, and remained elevated through d 21 postpartum. Of the 269 cows included in the data set, 117 cows (43.5%) had at least one postpartum hyperketonemic event (BHBA ≥1.2mmol/L), and 202 cows (75.1%) had at least one event of elevated postpartum NEFA concentrations (≥0.70mmol/L) between 3 and 21 d in milk. Area under the curve (AUC) was used to investigate relationships between metabolites over time. Overall, the correlations between transition period NEFA and BHBA AUC were weak. We detected a negative correlation between prepartum BHBA AUC and postpartum NEFA AUC (r=-0.26). A positive correlation existed between postpartum NEFA AUC and postpartum BHBA AUC; however, the correlation coefficient was low (r=0.26). Large variation was found between the day of maximum NEFA concentration within the first 21 d in milk and day of maximum BHBA concentration for the same period. The mean and median times of maximum NEFA concentration were 6.8 and 6 d, respectively, whereas the mean and median times of maximum BHBA were 9.6 and 8 d, respectively; however, the range in days for both the mean and median day of maximum concentrations was very large. Overall, our data set indicates a weak relationship between blood concentrations of NEFA

  9. Synergistic effects in solvent-extraction systems based on alkylsalicylic acids. III. Extraction of the trivalent lanthanides and yttrium from chloride media in the presence of dialkyl and diaryl sulphoxides

    Dialkyl and diaryl sulphoxides were found to cause synergistic shifts in the pH50 values for the extraction of the trivalent lanthanides and yttrium from sodium chloride media by solutions of alkylsalicylic acids in xylene. The extent of the synergistic shift for a given sulphoxide increases with increasing steric bulk of the alkylsalicylic acid used. With the homologous series of dialkyl sulphoxides R2SO, where R = n-butyl, n-hexyl, and n-octyl, there is little variation in the size of the synergistic shift for a given alkylsalicylic acid. For a series of sulphoxides containing similar numbers of carbon atoms, the extent of the shift increases with the introduction of alicyclic rings, but decreases when aromatic rings are introduced, for example, in the order of R: cyclohexyl > n-hexyl > phenyl, although the effect is not very marked. For a given extractant mixture, the pH50 values decrease from lanthanum to samarium and then increase from samarium to lutetium. The separation between the pH50 values for lanthanum and lutetium increases with increasing steric bulk of both the alkylsalicylic acid (HA) and the sulphoxide (L), but the separations between adjacent lanthanides are in all cases too small to be of any practical use. Slope-analysis treatment of metal-distribution data, and measurements of the solubility of the neodymium-alkylsalicylic acid complex in xylene solutions of the sulphoxides are consistent with the extraction of a mixed-ligand complex of the type NdA3L2. 22 refs., 4 figs., 4 tabs

  10. Co-extraction and co-stripping of U(VI) and Pu(IV) using tri-iso-amyl phosphate and tri-n-butyl phosphate in n-dodecane from nitric acid media under high loading conditions

    Sreenivasulu, Balija; Suresh, Ammath; Sivaraman, Nagarajan; Rao, P.R. Vasudeva [Indira Gandhi Centre for Atomic Research, Kalpakkam (India). Chemistry Group

    2016-08-01

    The extraction of Pu(IV) using 1.1 M solution of tri-iso-amyl phosphate (TiAP)/n-dodecane (DD) from plutonium nitrate solutions in nitric acid media was examined as a function of equilibrium aqueous phase metal ion concentration and equilibrium aqueous phase acidity at 303 K. The nitric acid concentration in the organic phase was measured as a function of equilibrium organic phase plutonium concentration. The co-extraction of U(VI) and Pu(IV) was studied using 1.1 M TiAP/DD system as a function of their equilibrium aqueous phase metal ion concentration and compared with 1.1 M tri-n-butyl phosphate (TBP)/n-DD system under identical conditions. Co-extraction and co-stripping of U(VI) and Pu(IV) were studied using 1.1 M TiAP/DD and 1.1 M TBP/DD systems in cross current mode to evaluate the number of stages required for the extraction and stripping of heavy metal ions (uranium and plutonium). The extraction and stripping efficiencies were calculated for both the systems. The saturation limit of the organic phase was also established in these studies.

  11. On Media Education

    Fedorov, Alexander

    2008-01-01

    This monograph analyzes the theory and practice of media education and media literacy. The book also includes the list of Russian media education literature and addresses of websites of the associations for media education.

  12. Otitis media with effusion

    OME; Secretory otitis media; Serous otitis media; Silent otitis media; Silent ear infection; Glue ear ... drains from the tube and is swallowed. Otitis media with effusion (OME) and ear infections are connected ...

  13. Basicity comparison for di-substituted 4-nitropyridine derivatives in polar non-aqueous media

    Acid dissociation, as well as cationic homoconjugation equilibria have been studied potentiometrically in systems involving four di-substituted 4-nitropyridines and conjugate cationic acids in the polar non-aqueous solvents - aprotic protophobic acetonitrile (AN) and propylene carbonate (PC), the amphiprotic methanol (MeOH), and in the aprotic protophilic dimethyl sulfoxide (DMSO). The influence of solvent effect on the obtained acidity constants has been discussed. The acidity constants (expressed as pKa values) were compared with those previously determined in another polar protophobic aprotic solvent - acetone (AC), and obtained for the unsubstituted pyridine (Py). A comparison of the acid dissociation constants determined in all media studied has proved that the strength of the cationic acids increases on going from acetonitrile through propylene carbonate, acetone, and methanol to dimethyl sulfoxide. Furthermore, the values of acidity constants in the non-aqueous media have shown that in all the solvents studied they change according to the substituent effects. It has been also found that substituted 4-nitropyridine derivatives studied exhibit no tendency towards cationic homoconjugation in acetonitrile, propylene carbonate, and methanol and dimethyl sulfoxide. Moreover, it has been demonstrated that the acid dissociation constants determined by potentiometric titration method in all the solutions investigated correlate well with the calculated energy parameters of the protonation reactions in the gaseous phase

  14. Irradiation effects on the storage and disposal of radwaste containing organic ion-exchange media. [3 functional forms of resin - sulfonic acid cation exchanger, quarternary ammonium anion exchanger and mixed bed combination of the two

    Swyler, K.J.; Dodge, C.J.; Dayal, R.

    1983-10-01

    Polystyrene-divinylbenzene (PS-DVB) based ion exchangers are commonly used in water demineralization or decontamination operations at nuclear facilities. Self-irradiation from sorbed radionuclides may affect the properties of radwaste containing these ion-exchange media. The effects of external irradiation on anion, cation, and mixed bed PS-DVB ion exchangers have been investigated under conditions relevant to radwaste storage and disposal. Three effects are emphasized in the present report: (1) release of acids, radionuclides or chemically aggressive species through radiolytic attack on the functional group, (2) radiolytic generation/uptake of corrosive or combustible gases, (3) effect of irradiation on solidification of resins in cement. Special consideration was placed on external variables such as radiation dose rate, resin chemical loading and moisture conditions, accessibility to atmospheric oxygen, and interactions in multicomponent systems. Such variables may affect the correspondence between laboratory results and field performance. 40 references, 24 figures, 28 tables.

  15. Carbohydrate/protein selection in a single meal correlated with plasma tryptophan and tyrosine ratios to neutral amino acids in fasting individuals.

    Møller, S E

    1986-01-01

    Plasma ratios of tryptophan (Trp) and tyrosine (Tyr) to their respective competing large neutral amino acids (LNAA) for brain uptake, serum insulin and plasma glucose concentrations were determined in 31 fasting healthy female subjects, and in two smaller groups of smokers and oral contraceptive users, who were subsequently allowed to compose individual breakfast meals from a selection of 25 dietary products. Additional blood samples were collected at 2 hr after the meal. Smokers consumed less carbohydrate (-22%) and total calories (-23%) and showed decreased basal serum insulin level, when compared to controls on the same age. Females on oral contraceptives consumed significantly more carbohydrate (+54%) and total calories (+32%) than comparable controls. In the 31 females there was no significant correlation between any of the biological variables and the intake of fat or total calories. The ratio of carbohydrate/protein eaten was significantly and directly correlated with age and with the sum of plasma ratios Trp/LNAA and Tyr/LNAA, and these independent variables associated with 37% of the variance in the ratio carbohydrate/protein consumed, as evaluated by multiple regression analysis. After the meal, the plasma ratio Tyr/LNAA was increased, whereas the ratio Trp/LNAA was decreased in subjects whose ratio carbohydrate/protein consumed was below the mean of the full sample, whereas subjects who consumed meals with a high ratio carbohydrate/protein showed an increase in plasma ratio Trp/LNAA. It is concluded that biological variables in man are significantly associated with the choice between nutrients with different carbohydrate and protein contents for breakfast. The changes in the plasma ratios Trp/LNAA and Tyr/LNAA after consumption were generally moderate. PMID:3797484

  16. Media Education Initiatives by Media Organizations: The Uses of Media Literacy in Hong Kong Media

    Chu, Donna; Lee, Alice Y. L.

    2014-01-01

    As more media organizations have engaged in media education, this paper investigates the goals and practices of these activities. This article coins media education initiatives by media organizations with the term "media-organization media literac"y (MOML). Four MOML projects in Hong Kong were selected for examination. Built on critical…

  17. Mukaiyama Aldol Reactions in Aqueous Media

    Kitanosono, Taku; Kobayashi, Shū

    2013-01-01

    Mukaiyama aldol reactions in aqueous media have been surveyed. While the original Mukaiyama aldol reactions entailed stoichiometric use of Lewis acids in organic solvents under strictly anhydrous conditions, Mukaiyama aldol reactions in aqueous media are not only suitable for green sustainable chemistry but are found to produce singular phenomena. These findings led to the discovery of a series of water-compatible Lewis acids such as lanthanide triflates in 1991. Our understanding on these be...

  18. Nature of Soil Acidity in Relation to Properties and Lime Requirement of Some Inceptisols

    A. K. DOLUI; S. BHATTACHARJEE

    2003-01-01

    Some Inceptisols representing the Singla catchment area in Karimgaunge district of Assam, India, were studied for lime requirement as influenced by the nature of soil acidity. The electrostatically bonded (EB)-H+ and EB-Al3+ acidities constituted 33 and 67 percent of exchangeable acidity while EB-H+, EB-Al3+,exchangeable and pH-dependent acidities comprised 6, 14, 20 and 80 percent of total potential acidity. The pH-dependent acidity made a major contribution towards the total potential acidity (67%~84%). Grand mean of lime requirement determined by the laboratory incubation method and estimated by the methods of New Woodruff, Woodruff and Peech as expressed in MgCaCO3 ha-1 was in the order: Woodruff (15.6) > New Woodruff (14.9) > Peech (5.1) > incubation (5.0). Correlations analysis among different forms of acidity and lime requirement methods with selected soil properties showed that pH in three media, namely water, 1 mol L-1 KCl and 0.01 mol L-1 CaCl2, had a significant negative correlation with different forms of acidity and lime requirement methods. Exchangeable Fe and Al showed significant positive correlations with EB-Al3+ acidity, exchangeable acidity, pH-dependent acidity and total potential acidity, and also lime requirement methods. Extractable Al showed positive correlations with different forms of acidity except EB-H+ and EB-Al3+ acidities. The lime requirement by different methods depended upon the extractable aluminium.Significant positive correlations existed between lime requirements and different forms of acidity of the soils except EB-H+ acidity and incubation method. The nature of soil acidity was mostly pH-dependent. Statistically, the Woodruff method did slightly better than the New Woodruff, incubation and Peech methods at estimating lime requirement and hence the Woodruff procedure may be recommended for routine soil testing because of its speed and simplicity.

  19. Determination of vanadium in stainless steel and Ni-base alloys by NBPHA spectrophotometric method combined with chloroform extraction separation in media of sulfuric-hydrofluoric acid

    A new method of rapid vanadium analysis was proposed. In this method, vanadium is directly extracted and determined from sample solutions in sulfuric-hydrofluoric acid. The interference of the coexisting elements can be ignored in this method. Take one gram of sample into a 200 ml beaker, and add 30 ml of aqua regia. Then heat and dissolve it, and add 14 ml of sulfuric acid (1+1) and 5 ml of phosphoric acid. After cooling, dissolve the salts with a small amount of water. Thereafter, transfer it with use of water into a polyethylene separatory funnel, add 10 ml of 46% hydrofluoric acid, and dilute to 50 ml. Then, add 4 ml iron (II) ammonium sulfate solution (10%) and mix it thoroughly. Allow to stand for two or three minutes, add 10 ml of 45% ammonium persulfate solution and mix it thoroughly again. Allow to stand for about five minutes. Then, add exactly 20 ml of BPHA-chloroform solution (0.1%) and shake and mix it vigorously for two minutes. After a while, transfer the chloroform complex into a 10 mm cell through a piece of absorbent cotton. Then, determine vanadium by measuring the absorbance at the wave length of 530 nm against a chloroform reference. This method can be applicable to the analysis of vanadium in other metals and alloys than stainless steel and Ni-base alloys. (Iwakiri, K.)

  20. Quantum free energy landscapes from ab initio path integral metadynamics: Double proton transfer in the formic acid dimer is concerted but not correlated

    Ivanov, Sergei D., E-mail: sergei.ivanov@unirostock.de; Grant, Ian M.; Marx, Dominik [Lehrstuhl für Theoretische Chemie, Ruhr–Universität Bochum, 44780 Bochum (Germany)

    2015-09-28

    With the goal of computing quantum free energy landscapes of reactive (bio)chemical systems in multi-dimensional space, we combine the metadynamics technique for sampling potential energy surfaces with the ab initio path integral approach to treating nuclear quantum motion. This unified method is applied to the double proton transfer process in the formic acid dimer (FAD), in order to study the nuclear quantum effects at finite temperatures without imposing a one-dimensional reaction coordinate or reducing the dimensionality. Importantly, the ab initio path integral metadynamics technique allows one to treat the hydrogen bonds and concomitant proton transfers in FAD strictly independently and thus provides direct access to the much discussed issue of whether the double proton transfer proceeds via a stepwise or concerted mechanism. The quantum free energy landscape we compute for this H-bonded molecular complex reveals that the two protons move in a concerted fashion from initial to product state, yet world-line analysis of the quantum correlations demonstrates that the protons are as quantum-uncorrelated at the transition state as they are when close to the equilibrium structure.

  1. Quantum free energy landscapes from ab initio path integral metadynamics: Double proton transfer in the formic acid dimer is concerted but not correlated

    With the goal of computing quantum free energy landscapes of reactive (bio)chemical systems in multi-dimensional space, we combine the metadynamics technique for sampling potential energy surfaces with the ab initio path integral approach to treating nuclear quantum motion. This unified method is applied to the double proton transfer process in the formic acid dimer (FAD), in order to study the nuclear quantum effects at finite temperatures without imposing a one-dimensional reaction coordinate or reducing the dimensionality. Importantly, the ab initio path integral metadynamics technique allows one to treat the hydrogen bonds and concomitant proton transfers in FAD strictly independently and thus provides direct access to the much discussed issue of whether the double proton transfer proceeds via a stepwise or concerted mechanism. The quantum free energy landscape we compute for this H-bonded molecular complex reveals that the two protons move in a concerted fashion from initial to product state, yet world-line analysis of the quantum correlations demonstrates that the protons are as quantum-uncorrelated at the transition state as they are when close to the equilibrium structure

  2. Efficient, validated method for detection of mycobacterial growth in liquid culture media by use of bead beating, magnetic-particle-based nucleic acid isolation, and quantitative PCR.

    Plain, Karren M; Waldron, Anna M; Begg, Douglas J; de Silva, Kumudika; Purdie, Auriol C; Whittington, Richard J

    2015-04-01

    Pathogenic mycobacteria are difficult to culture, requiring specialized media and a long incubation time, and have complex and exceedingly robust cell walls. Mycobacterium avium subsp. paratuberculosis (MAP), the causative agent of Johne's disease, a chronic wasting disease of ruminants, is a typical example. Culture of MAP from the feces and intestinal tissues is a commonly used test for confirmation of infection. Liquid medium offers greater sensitivity than solid medium for detection of MAP; however, support for the BD Bactec 460 system commonly used for this purpose has been discontinued. We previously developed a new liquid culture medium, M7H9C, to replace it, with confirmation of growth reliant on PCR. Here, we report an efficient DNA isolation and quantitative PCR methodology for the specific detection and confirmation of MAP growth in liquid culture media containing egg yolk. The analytical sensitivity was at least 10(4)-fold higher than a commonly used method involving ethanol precipitation of DNA and conventional PCR; this may be partly due to the addition of a bead-beating step to manually disrupt the cell wall of the mycobacteria. The limit of detection, determined using pure cultures of two different MAP strains, was 100 to 1,000 MAP organisms/ml. The diagnostic accuracy was confirmed using a panel of cattle fecal (n=54) and sheep fecal and tissue (n=90) culture samples. This technique is directly relevant for diagnostic laboratories that perform MAP cultures but may also be applicable to the detection of other species, including M. avium and M. tuberculosis. PMID:25609725

  3. Body Image, Media, and Eating Disorders

    Derenne, Jennifer L.; Beresin, Eugene V.

    2006-01-01

    Objective: Eating disorders, including obesity, are a major public health problem today. Throughout history, body image has been determined by various factors, including politics and media. Exposure to mass media (television, movies, magazines, Internet) is correlated with obesity and negative body image, which may lead to disordered eating. The…

  4. Study of adsorption properties and inhibition of mild steel corrosion in hydrochloric acid media by water soluble composite poly (vinyl alcohol-o-methoxy aniline)

    R. Karthikaiselvi; S. Subhashini

    2014-01-01

    The efficiency of new water soluble composite namely, poly (vinyl alcohol-o-methoxy aniline) PVAMOA has been studied for corrosion inhibition of mild steel in 1 M hydrochloric acid (HCl). Corrosion inhibition was investigated using weight loss, potentiodynamic polarization and electrochemical impedance studies. The kinetic and thermodynamic parameters for mild steel corrosion and inhibitor adsorption respectively, were determined and discussed. The adsorption of PVAMOA on the mild steel surfa...

  5. Use of ferric sulfate: acid media for the desulfurization of model compounds of coal. [Dibenzothiophene, diphenyl sulfide, di-n-butyl sulfide

    Clary, L.R.; Vermeulen, T.; Lynn, S.

    1980-12-01

    The objective of this work has been to investigate the ability of ferric sulfate-acid leach systems to oxidize the sulfur in model compounds of coal. Ferric iron-acid leach systems have been shown to be quite effective at removal of inorganic sulfur in coal. In this study, the oxidative effect of ferric iron in acid-leach systems was studied using dibenzothiophene, diphenyl sulfide, and di-n-butyl sulfide as models of organic sulfur groups in coal. Nitrogen and oxygen, as well as various transition metal catalysts and oxidants, were utilized in this investigation. Dibenzothiophene was found to be quite refractory to oxidation, except in the case where metavanadate was added, where it appears that 40% oxidation to sulfone could have occurred per hour at 150/sup 0/C and mild oxygen pressure. Diphenyl sulfide was selectively oxidized to sulfoxide and sulfone in an iron and oxygen system. Approximately 15% conversion to sulfone occurred per hour under these conditions. Some of the di-n-butyl sulfide was cracked to 1-butene and 1-butanethiol under similar conditions. Zinc chloride and ferric iron were used at 200/sup 0/C in an attempt to desulfonate dibenzothiophene sulfone, diphenyl sulfone, and di-n-butyl sulfone. Di-n-butyl sulfone was completely desulfurized on one hour and fragmented to oxidized parafins, while dibenzothiophene sulfone and diphenyl sulfone were unaffected. These results suggest that an iron-acid leach process could only selectively oxidize aryl sulfides under mild conditions, representing only 20% of the organic sulfur in coal (8% of the total sulfur). Removal through desulfonation once selective sulfur oxidation had occurred was only demonstrated for alkyl sulfones, with severe oxidation of the fragmented paraffins also occurring in one hour.

  6. Application of surfactant-templated ordered mesoporous material as sorbent in micro-solid phase extraction followed by liquid chromatography-triple quadrupole mass spectrometry for determination of perfluorinated carboxylic acids in aqueous media.

    Lashgari, Maryam; Basheer, Chanbasha; Kee Lee, Hian

    2015-08-15

    In the present study, micro-solid phase extraction (µ-SPE) followed by liquid chromatography-triple tandem mass spectrometery (LC-MS/MS) was developed for the determination of perfluorocarboxylic acids (PFCAs) at trace levels in water samples. The µ-SPE device comprised of a porous polypropylene membrane bag containing 5mg sorbent. The membrane bag acted as a clean-up filter and prevented matrix compounds from interfering with the extraction process. Analysis was carried out by LC-MS/MS in negative electrospray ionization mode. MS/MS parameters were optimized for multiple reaction monitoring. Calcined and non-calcined MCM-41, as silica-ordered mesoporous materials, were used as sorbents in µ-SPE for the extraction of five PFCAs-perfluoropentanoic acid (PFPA), perfluoroheptanoic acid (PFHpA), perfluorooctanoic acid (PFOA), perfluorononanoic acid (PFNA), and perfluorodecanoic acid (PFDA)-from aqueous media. The performances of these two sorbents were compared with other sorbents such as octadecylsilane (C18) modified silica, HayeSep-A, HayeSep-B, and Porapak-R. It was found that non-calcined MCM-41 showed better extraction performance for the analytes considered. Parameters influencing extraction efficiency, such as desorption time, extraction time, desorption solvent, and salt concentration, were investigated. The effect of the matrix on MS signals (suppression or enhancement) was also evaluated. Only minor effects on ionization efficiencies were observed. The developed method proved to be convenient and offered good sensitivity and reproducibility. The limits of detection ranged from 0.02 to 0.08ng L(-1), with a relative standard deviations between 1.9 and 10.5. It was successfully applied to the extraction of PFCAs in river and rain water samples. As expected from the ubiquitous nature of PFCAs, contamination at low levels was detected for some analytes in the samples (with the highest concentration recorded for PFOA). Satisfactory relative recoveries ranging

  7. Media Clusters and Media Cluster Policies

    Karlsson, Charlie; Picard, Robert

    2011-01-01

    Large media clusters have emerged in a limited number of large cities, characterizing the geographical concentration of the global media industry. This paper explores the reasons behind the localization patterns of media industries, the effect of the rapid advancement of Information and Communication Technologies (ICT) on media clusters and the role of media cluster policies. One might draw the conclusion that with the developments of the ICT sector and the fact that there are no raw material...

  8. Elution of nickel ions from alginate beads in an acid media; Elucion de iones de niquel desde esferas de alginato en un medio acido

    Aracena, A.; Carcamo, F.; Jerez, O.; Constanzo, R.

    2016-05-01

    Elution of nickel ions from alginate beads was studied in a temperature range of 2 to 80 degree centigrade and a sulfuric acid concentration between 0.005 to 2.5 g L{sup -}1. The elution mechanism was established by ion exchange between nickel and ions protons, obtaining a value of 93% elution at a temperature of 80 degree centigrade and a H{sub 2}SO{sub 4} concentration of 0.25 g L{sup -}1. The influence of other acids on nickel elution was also studied. The nickel elution rate was significantly influenced by temperature and concentration of H{sub 2}SO{sub 4}. Elution kinetics of nickel ions was studied, and the 1-(1-α){sup 1}/3=k{sub a}ppt model properly described the kinetics of this reaction. The dependence of nickel elution on the sulfuric acid concentration was of the order of 0.33. Moreover, the intrinsic rate constants were determined and an activation energy value of 54.5 kJ mol{sup -}1 was obtained for the temperature range studied. The results indicated that the nickel elution is a process controlled by chemical reactions. (Author)

  9. Electrodeposited ultrafine NbOx, ZrOx, and TaO x nanoparticles on carbon black supports for oxygen reduction electrocatalysts in acidic media

    Seo, Jeongsuk

    2013-09-06

    A remarkable electrocatalytic activity was obtained for the oxygen reduction reaction (ORR) in acidic solutions on ultrafine nano-oxide catalysts based on group IV or V elements. By potentiostatic electrodepostion in nonaqueous solutions at 298 K followed by heat treatment in H2 gas, highly dispersed fine nanoparticles of NbOx, ZrOx, and TaOx with sizes of less than 5 nm were prepared and deposited on carbon black (CB) loaded electrodes. These oxide nanoparticles showed high catalytic activities with high onset potentials of 0.96 VRHE (NbOx), 1.02 VRHE (ZrOx), and 0.93 V RHE (TaOx) for the ORR. Owing to the high chemical stability of group IV and V oxides, the catalysts were very stable during the ORR in acidic solutions. Surface characterization and chemical identification were performed using scanning transmission electron microscopy (STEM), energy dispersive X-ray spectroscopy (EDS), and X-ray photoelectron spectroscopy (XPS). All results clearly indicate the formation of nano-oxide electrocatalysts that show an outstanding ORR performance, whereas the bulk oxides are not active because of the absence of electronic conductivity. The present work demonstrates potential candidates for highly stable, non-noble-metal cathode catalysts for polymer electrolyte fuel cells (PEFCs), where the catalysts are exposed to highly acidic and oxidizing conditions. © 2013 American Chemical Society.

  10. A rapid method for determining arachidonic:eicosapentaenoic acid ratios in whole blood lipids: correlation with erythrocyte membrane ratios and validation in a large Italian population of various ages and pathologies

    Corsetto Paola

    2010-01-01

    Full Text Available Abstract Background Omega-3 and -6 polyunsaturated fatty acids (LCPUFA, are important for good health conditions. They are present in membrane phospholipids. The ratio of total n-6:n-3 LCPUFA and arachidonic acid:eicosapentaenoic acid (AA and EPA, should not exceed 5:1. Increased intake of n-6 and decreased consumption of n-3 has resulted in much higher, ca 10/15:1 ratio in RBC fatty acids with the possible appearance of a pathological "scenario". The determination of RBC phospholipid LCPUFA contents and ratios is the method of choice for assessing fatty acid status but it is labour intensive and time consuming. Aims of the study [i] To describe and validate a rapid method, suitable for large scale population studies, for total blood fatty acid assay; [ii] to verify a possible correlation between total n-6:n-3 ratio and AA:EPA ratios in RBC phospholipids and in whole-blood total lipids, [iii] to assess usefulness of these ratio as biomarkers of LCPUFA status. Methods 1 Healthy volunteers and patients with various pathologies were recruited. 2 Fatty acid analyses by GC of methyl esters from directly derivatized whole blood total lipids and from RBC phospholipids were performed on fasting blood samples from 1432 subjects categorised according to their age, sex and any existing pathologies. AA:EPA ratio and the total n-6:n-3 ratio were determined. Results AA:EPA ratio is a more sensitive and reliable index for determining changes in total blood fatty acid and it is correlated with the ratio derived from extracted RBC phospholipids. Conclusions The described AA:EPA ratio is a simple, rapid and reliable method for determining n-3 fatty acid status.

  11. Effect of Yttrium Ion Implantation on the Corrosion Resistance of Stainless Steel AISI 316 L Type in Sulfuric Acid (H2SO4, pH = 1.06) Media

    The effect of yttrium ion implantation on the corrosion resistance of stainless steel AISI 316 L type in sulfuric acid (H2SO4, pH = 1.06) is presented in this paper. Implantation of yttrium ion was carried out by varying the ion dose implanted into target at ion energy of 100 keV. Corrosion resistance properties experiments was carried out electrochemically in sulfuric acid media (H2SO4, pH = 1.06). Yttrium ion implanted into target was analyzed using EDAXS (Energy Dispersive Analysis X-Rays Spectroscopy). It has been found that before implantation, the corrosion current density of the samples was Icorr = 0.2 μA/cm2 (52 x 10-4 mpy). After the samples were implanted at ion dose 1.7 x 1017 ion /cm2, 2.1 x 1017 ion /cm2, 2.6 x 1017 ion /cm2, 3.0 x 1017 ion /cm2 and 3.5 x 1017 ion /cm2, the corrosion current density were 0.033 μA/cm2 (8.581 mpy), 0.033 μA/cm2 (8.581 mpy), 0.01 μA/cm2 (2.6 mpy), 0.033 μA/cm2 (8.581 mpy), and 0.066 μA/cm2 (17.162 mpy) respectively. From elemental analysis using EDAXS, it has been found that before implantation by yttrium ion, the contents of yttrium was 0 %, and after implantation at those ion doses, the contents of yttrium were 0.15 %, 0.17 %, 0.20 %, 0.32 % and 0.43 % weight. From these data, it could be concluded that the best corrosion resistance in sulfuric acid (pH = 1.06) was achieved at 0.20 % weight of yttrium. (author)

  12. Corrosion behavior of copper thin films deposited by EB-PVD technique on thermally grown silicon dioxide and glass in hydrochloric acid media

    Copper thin films were deposited on oxidized single crystal silicon and glass surfaces, at 70 deg. C and 150 deg. C substrate temperature using Electron Beam-Physical Vapor Deposition technique. The morphology and crystal orientation of the deposited film were investigated by SEM and XRD, respectively. Corrosion behavior of these films in hydrochloric acid was studied by potentiodynamic polarization method. Results showed that the corrosion resistance of CG 70 (deposit on glass at 70 deg. C substrate temperature) was higher than all deposits and than copper sheet because of its higher ability to form passive layer.

  13. Toward an Active and Stable Catalyst for Oxygen Evolution in Acidic Media: Ti-Stabilized MnO2

    Frydendal, Rasmus; Paoli, Elisa Antares; Chorkendorff, Ib;

    2015-01-01

    undercoordinated surface sites of MnO2 with a stable oxide is developed here. TiO2 stands out as the most promising of the different oxides in the simulations. This prediction is experimentally verified by testing sputter-deposited thin films of MnO2 and Ti-MnO2. A combination of electrochemical measurements......Catalysts are required for the oxygen evolution reaction, which are abundant, active, and stable in acid. MnO2 is a promising candidate material for this purpose. However, it dissolves at high overpotentials. Using first-principles calculations, a strategy to mitigate this problem by decorating...

  14. How European PR practitioners handle digital and social media

    P. Verhoeven; R. Tench; A. Zerfass; A. Moreno; D. Verčič

    2012-01-01

    The European Communication Monitor (ECM) 2010 showed that digital communication and social media have grown in importance in the media mix of European organizations. Both new media types are positively correlated to the perceived impact of public relations (PR) in the organization. Specifically soci

  15. Highly active carbon supported ternary PdSnPtx (x=0.1-0.7) catalysts for ethanol electro-oxidation in alkaline and acid media.

    Wang, Xiaoguang; Zhu, Fuchun; He, Yongwei; Wang, Mei; Zhang, Zhonghua; Ma, Zizai; Li, Ruixue

    2016-04-15

    A series of trimetallic PdSnPtx (x=0.1-0.7)/C catalysts with varied Pt content have been synthesized by co-reduction method using NaBH4 as a reducing agent. These catalysts were characterized using X-ray diffraction (XRD), transmission electron microscopy (TEM), high resolution transmission electron microscopy (HRTEM), energy dispersive X-ray spectroscopy (EDX), X-ray photoelectron spectroscopy (XPS), cyclic voltammetry (CV) and chronoamperometry (CA). The electrochemical results show that, after adding a minor amount of Pt dopant, the resultant PdSnPtx/C demonstrated more superior catalytic performance toward ethanol oxidation as compared with that of mono-/bi-metallic Pd/C or PdSn/C in alkaline solution and the PdSnPt0.2/C with optimal molar ratio reached the best. In acid solution, the PdSnPt0.2/C also depicted a superior catalytic activity relative to the commercial Pt/C catalyst. The possible enhanced synergistic effect between Pd, Sn/Sn(O) and Pt in an alloyed state should be responsible for the as-revealed superior ethanol electro-oxidation performance based upon the beneficial electronic effect and bi-functional mechanism. It implies the trimetallic PdSnPt0.2/C with a low Pt content has a promising prospect as anodic electrocatalyst in fields of alkali- and acid-type direct ethanol fuel cells. PMID:26851453

  16. Geographic Media Literacy

    Lukinbeal, Chris

    2014-01-01

    While the use of media permeates geographic research and pedagogic practice, the underlying literacies that link geography and media remain uncharted. This article argues that geographic media literacy incorporates visual literacy, information technology literacy, information literacy, and media literacy. Geographic media literacy is the ability…

  17. SAFETY IN ONLINE MEDIA – FREEDOM OF THE MEDIA; SAFETY OF MEDIA ACTORS AND MEDIA EDUCATION

    Moeller, Ch

    2013-01-01

    In this paper, prepared for the international conference ‘Mass Media – Society – Education: Media Safety Problems’ at the Chelyabinsk State University’s Department for Journalism and Media Education from September 30 – October 3, 2013, I would like to address three dimensions of media safety and security in online media.

  18. Organophosphinic, phosphonic acids and their binary mixtures as extractants for molybdenum(VI) and uranium(VI) from aqueous HCl media

    Extraction studies of uranium(VI) and molybdenum(VI) with organophosphoric, phosphinic acid and its thiosubstituted derivatives have been carried out from 0.1-1.0M HCl solutions. The extracted species are proposed to be UO2R2 and MoO2CIR on the basis of slope analysis for uranium(VI) and molybdenum(VI), respectively. The extraction efficiencies of PC-88A, Cyanex 272, Cyanex 301 and Cyanex 302 in the extraction of molybdenum(VI) and uranium(VI) are compared. Synergistic effects have been studied with binary mixtures of extractants. Separation of molybdenum(VI) from uranium(VI) is feasible by Cyanex 301 from 1M HCl, the separation factor logβ being 2.3. (author) 20 refs.; 5 figs.; 14 tabs

  19. Extraction of scandium from various media with triisoamyl phosphate. Communication 1. extraction of Sc and impurity metals from aqueous nitric acid solutions

    The main features of extraction of Sc from aqueous nitric acid solutions with triisoamyl phosphate (TIAP) were studied. It was shown that Sc passes into the organic phase in the form of Sc(NO3)3·3TIAP. The extraction isotherms of Sc from its aqueous HNO3 solutions and from those containing salting-out agents (LiNO3, NH4NO3) with TIAP in dodecane were obtained. The distribution factor of Sc was studied in relation to the concentrations of TIAP, salting-out agent, and HNO3. The extraction of Sc and impurity metals (Zr, Th, REE) with TIAP was studied using a tracer technique at widely varied HNO3 concentration in the aqueous phase. The separation factors of Sc from impurity metals were determined

  20. Media Literacy in Times of Media Divides

    Kaja Žuran

    2013-12-01

    Full Text Available We live in a post-modern society, an information society, a society based around knowledge and participation, and above all in a media society. In a media culture where media holds a dominant position, we cannot overlook the emerging idea of a ‘media divide’ within the frame of media education, media literate individuals and the expansion of the traditional concept of media literacy. Firstly, we are in an era of technological revolution, and it is time to consider the meaning and function of media and how we experience it in our everyday life. Secondly, as a society we are subject to intense media invasion and we all need to learn how to use it to our benefit and apply a critical and autonomous perspective towards selecting media content. Otherwise the media divide between the media literate and illiterate will widen; but is there even a chance to overcome the supposed divide between those who are formally media educated and those who are not?

  1. Passivity of OC404 steel modified electrochemically with CeO2-Ce2O3 layers in sulfuric acid media

    The effect of cerium oxides film, formed electrochemically on OC404 stainless steel (SS), upon the corrosion behavior of steel in 0.1N H2SO4 was investigated. The modification of the steel surface by deposition of cerium oxides films was found to improve the steel corrosion resistance. A linear dependence between the stationary corrosion potential of the cerium oxides/SS system and the cerium concentration in the oxide film was established. The shift of the corrosion potential in the positive direction was found to depend on the proceeding of a depolarizing cathode reaction of CeO2 reduction (instead of the hydrogen depolarizing reaction) occurring on the cathodic zones, formed by this oxide. On the basis of XPS analyses of the samples, subjected to real corrosion under the conditions of self-dissolution, a pronounced drop of the surface concentration of CeO2 was established. This is a proof of the occurrence of an effective cathode process of CeO2 reduction to Ce2O3, which was then dissolved in H2SO4. Data were obtained (XPS) on the composition and structure of the surface film (SEM) after electrodeposition of cerium oxides and after corrosion in the sulfuric acid medium under consideration for time intervals ranging from 50 up to 1000 h. The ICP-AES studies acquired data on the quantity of dissolved elements, forming the passive layer. After exposure to the corrosive medium, the deposited layer showed enrichment in oxides of chromium and aluminium. The passive film on stainless steel, modified in this way, proved to be more stable to the effect of aggressive sulfuric acid medium, compared to the case of natural passive film.

  2. Passivity of OC404 steel modified electrochemically with CeO{sub 2}-Ce{sub 2}O{sub 3} layers in sulfuric acid media

    Stoyanova, E.; Guergova, D. [Institute of Physical Chemistry, Bulgarian Academy of Sciences, ' Acad. G. Bonchev' Str., Block 11, Sofia 1113 (Bulgaria); Stoychev, D., E-mail: stoychev@ipchp.ipc.bas.b [Institute of Physical Chemistry, Bulgarian Academy of Sciences, ' Acad. G. Bonchev' Str., Block 11, Sofia 1113 (Bulgaria); Avramova, I.; Stefanov, P. [Institute of General and Inorganic Chemistry, Bulgarian Academy of Sciences, ' Acad. G. Bonchev' Str., Block 11, Sofia 1113 (Bulgaria)

    2010-02-01

    The effect of cerium oxides film, formed electrochemically on OC404 stainless steel (SS), upon the corrosion behavior of steel in 0.1N H{sub 2}SO{sub 4} was investigated. The modification of the steel surface by deposition of cerium oxides films was found to improve the steel corrosion resistance. A linear dependence between the stationary corrosion potential of the cerium oxides/SS system and the cerium concentration in the oxide film was established. The shift of the corrosion potential in the positive direction was found to depend on the proceeding of a depolarizing cathode reaction of CeO{sub 2} reduction (instead of the hydrogen depolarizing reaction) occurring on the cathodic zones, formed by this oxide. On the basis of XPS analyses of the samples, subjected to real corrosion under the conditions of self-dissolution, a pronounced drop of the surface concentration of CeO{sub 2} was established. This is a proof of the occurrence of an effective cathode process of CeO{sub 2} reduction to Ce{sub 2}O{sub 3}, which was then dissolved in H{sub 2}SO{sub 4}. Data were obtained (XPS) on the composition and structure of the surface film (SEM) after electrodeposition of cerium oxides and after corrosion in the sulfuric acid medium under consideration for time intervals ranging from 50 up to 1000 h. The ICP-AES studies acquired data on the quantity of dissolved elements, forming the passive layer. After exposure to the corrosive medium, the deposited layer showed enrichment in oxides of chromium and aluminium. The passive film on stainless steel, modified in this way, proved to be more stable to the effect of aggressive sulfuric acid medium, compared to the case of natural passive film.

  3. 2012年丰都县酸雨特征及其相关分析%Characteristic of Acid Rain of Fengdu in 20 1 2 and Its Correlation Analysis

    郭小路

    2014-01-01

    The acid rain situation in Fengdu District was studied according to the rainfall monitoring data of this re-gion in 2012.It came to the conclusion that the acid rain pollution was serious in Fengdu District.The acid rain frequency in every month was above 90%,the rainfall acidity changed obviously from season to season and the se-verity was higher in winter than in summer.SO2-4 was the major anion in the rainfall which should be sulfate acid rain,and the correlation matrix analysis showed the definite correlation among the concentration of SO2-4 ,NO3-and F-in the rainfall.%根据2012年丰都县降水监测资料,对该地区的酸雨状况进行研究。结果表明,丰都县酸雨污染状况较重,各月的酸雨频率均在90%以上,降雨酸性的季节变化明显,冬季较夏季高。降雨成分中以SO2-4为主要阴离子,仍为硫酸型酸雨。相关矩阵分析表明,SO2-4、NO3-、F-相关性较好。

  4. The Attenuation of Correlation Coefficients: A Statistical Literacy Issue

    Trafimow, David

    2016-01-01

    Much of the science reported in the media depends on correlation coefficients. But the size of correlation coefficients depends, in part, on the reliability with which the correlated variables are measured. Understanding this is a statistical literacy issue.

  5. Corporate Media Governance

    Kempen, Petrus Cornelis

    2011-01-01

    The media can make or break a reputation. This being said, it seems to be essential for companies, governments and institutions to pay specific attention to corporate media management in their daily operations. However, this thesis shows that they often neglect to pay adequate attention to corporate media management. This is primarily due to the complexity of the corporate media process and corporate media management and the scope of a possible media impact. This thesis argues that corporate ...

  6. Turkish Media Elites

    D. Ali Arslan

    2008-01-01

    The media is one of the most important institutions in society. It is a reality that media play very substantial role in the production and social distribution of knowledge. In addition to that, mass media provides the greatest communication opportunities to the people. Also, contemporary media provides very distinctive weapons to obtain power, wealth and prestige in the society. If media owners and elites are so powerful, the identification of media elites is of great importance. Hence, this...

  7. Social media marketing

    Chudán, Jakub

    2013-01-01

    The “Social media marketing” diploma thesis focuses on social media marketing, with an analysis of potential social media sites usage as the main goal. The theoretical part focuses on social media and social media marketing. The practical part contains a case study, in which social media marketing on Facebook is created. A strategy proposal is made, based on the case study, emphasizing suitable ways of a proper use of Facebook for marketing, identifying various hurdles that companies are faci...

  8. Media and Democracy

    Curran, James P.

    2011-01-01

    Media and Democracy addresses key topics and themes in relation to democratic theory, media and technology, comparative media studies, media and history, and the evolution of media research. For example: How does TV entertainment contribute to the democratic life of society? Why are Americans less informed about politics and international affairs than Europeans? How should new communications technology and globalisation change our understanding of the democratic role of the media? ...

  9. Reduction of novel circulating long-chain fatty acids in colorectal cancer patients is independent of tumor burden and correlates with age

    Tomonaga Takeshi

    2010-11-01

    Full Text Available Abstract Background Serum levels of novel hydroxy polyunsaturated ultra long-chain fatty acids (hPULCFAs have been previously shown to be reduced in pre-treatment CRC patients compared to disease-free subjects, independent of disease stage. However, whether reduced levels of hPULCFAs result from the presence of cancer is currently unknown, as is the distribution of hPULCFAs in the general population. The following studies were carried out to assess whether conventional therapy would result in restoration of systemic hPULCFAs in CRC patients, and to investigate the relationship between hPULCFA levels and age. Methods Tandem mass spectrometry was used to determine serum levels of the 28 carbon-containing hPULCFA C28H46O4 (CRC-446 in the following cohorts: two independent Japanese CRC populations following surgical tumor removal (n = 86, a North American Caucasian CRC cohort (n = 150 following post-surgery combination chemo/radiation therapy, 990 randomly selected anonymized serum samples from subjects ranging between 11 and 99 years of age, as well as longitudinally collected serum samples from healthy normals (n = 8, up to 90 weeks and stage IV CRC subjects on combination therapy (n = 12, up to 63 weeks. Results Serum CRC-446 levels in CRC subjects were significantly lower than controls (mean of 0.297 ± 0.07 ug/ml in controls versus 0.092 ± 0.03 in CRCs, p 0.05 between pre vs post surgery. CRC-446 levels showed a strong inverse association with age (p Conclusions Our findings show that CRC-446 levels are not affected by conventional CRC treatment and inversely correlate with age, which suggest that reduced serum CRC-446 levels likely exist prior to the development of CRC. Extrapolation of the results to a simple screening scenario showed that, compared to fecal blood testing, pre-colonoscopy screening using serum CRC-446 levels would require 80% fewer colonoscopies, would identify risk in subjects under the age of 50, and would result in

  10. Analysis of a two-phase system of mass transfer and electro-reduction of uranium(VI) in nitric acid-hydrazine media

    Simulation for a dynamic analysis of the electrolytic preparation of U(IV) in two-phases system, which consisted of mass transfer of U(VI) from TBP phase into HNO3 solution and electrolytic reduction of U(VI) to U(IV) at a cathode in aqueous phase, was carried out in order to establish the most suitable operating condition and best electrode area as basic design data for the system. It was found that maintaining an appropriate mass transfer rate was more significant rather than enlarging the surface area of the cathode for more effective production yield of U(IV). The electrode area and the operation time affected deeply the production composition of U(IV) in the resulting aqueous phase. And optimal electrode areas were evaluated to meet production criteria of U(IV) of resulting solution in several system conditions. Though about 0.37M HNO3 was preferable to prepare the solution of U(IV), nitric acid concentration should be higher than 0.5M to prevent a hydrolysis of U(IV) in the aqueous phase. 6 figs., 24 refs. (Author)

  11. Solvent extraction studies with some fission product elements from nitric acid media employing tri-iso-amyl phosphate and tri-n-butyl phosphate as extractants

    Tri-iso-amyl phosphate (TiAP) has been identified as an alternate extractant to tri-n-butyl phosphate (TBP) for the reprocessing of fast reactor fuels. In the present work, extraction behaviour of some fission product elements such as Zr(IV), RuNO(III), TcO-4, La(III), Ce(III) and Nd(III) along with Am(III) has been investigated with 1.1 M solutions of TiAP and TBP in n-alkane diluents from nitric acid medium. The extraction of Zr(IV) has been evaluated with unirradiated and gamma irradiated solvents as a function of organic phase uranium(VI) loading. The influence of degradation products of TiAP and TBP on the extraction behaviour of fission products has also been examined. The effect of diluent degradation products and effect of alkali wash on the extraction of Zr(IV) is discussed. The formation of interfacial deposits during the washing of gamma irradiated solvents with alkali solution is also discussed. (author)

  12. Addition of IrO2 to RuO2+TiO2 coated anodes and its effect on electrochemical performance of anodes in acid media

    Farhad Moradi

    2014-04-01

    Full Text Available Ternary mixed metal oxide coatings with the nominal composition IrxRu(0.6−xTi0.4O2 (x=0, 0.1, 0.2, 0.3 on the titanium substrate were prepared by thermal decomposition of a chloride precursor mixture. Surface morphology and microstructure of the coatings were investigated by Scanning electron microscopy (SEM, Field emission scanning electron microscopy (FE-SEM and X-ray diffraction (XRD analysis. Systematic study of electrochemical properties of these coatings was performed by cyclic voltammetry (CV and polarization measurements. The corrosion behavior of the coatings was evaluated under accelerated conditions (j=2 A cm−2 in acidic electrolyte. The role of iridium oxide admixture in the change of electrocatalytic activity and stability of Ru0.6Ti0.4O2 coating was discussed. Small addition of IrO2 can improve the stability of the RuO2+TiO2 mixed oxide, while the electrocatalytic activity for oxygen evolution reaction (OER is decreased. The shift of redox potentials for Ru0.6Ti0.4O2 electrode that is slightly activated with IrO2 and improvement in the stability can be attributed to the synergetic effect of mixed oxide formation.

  13. Analysis of the formation of Ta{sub 2}O{sub 5} passive films in acid media through mechanistic modeling

    Cabrera-Sierra, R., E-mail: roma_ipn@yahoo.com [Instituto Politecnico Nacional, Escuela Superior de Ingenieria Quimica e Industrias Extractivas, Departamento de Ingenieria Quimica Industrial, UPALM Ed. 7, 1er. Piso CP 07738, D.F. (Mexico); Vazquez-Arenas, J. [Chemical Engineering Department, University of Waterloo, 200 University Avenue West, Waterloo, Ontario N2L 3G (Canada); Cardoso, S. [Instituto Politecnico Nacional, Escuela Superior de Ingenieria Quimica e Industrias Extractivas, Departamento de Ingenieria Quimica Industrial, UPALM Ed. 7, 1er. Piso CP 07738, D.F. (Mexico); Luna-Sanchez, R.M. [Universidad Autonoma Metropolitana-Azcapotzalco, Departamento de Energia, Av. San Pablo No. 180, Col. Reynosa Tamaulipas, CP 02200, D.F. (Mexico); Trejo, M.A. [Instituto Politecnico Nacional, Escuela Superior de Ingenieria Quimica e Industrias Extractivas, Departamento de Ingenieria Quimica Industrial, UPALM Ed. 7, 1er. Piso CP 07738, D.F. (Mexico); Marin-Cruz, J. [Instituto Mexicano del Petroleo, Coordinacion de Ingenieria Molecular, Competencia de Quimica Aplicada. Eje Central Lazaro Cardenas Norte 152, CP 07730, D.F. (Mexico); Hallen, J.M. [Instituto Politecnico Nacional, Escuela Superior de Ingenieria Quimica e Industrias Extractivas, Departamento de Ingenieria Quimica Industrial, UPALM Ed. 7, 1er. Piso CP 07738, D.F. (Mexico)

    2011-09-30

    Electrochemical impedance spectroscopy (EIS) analyses are carried out to evaluate the passive features of tantalum oxide films (Ta{sub 2}O{sub 5}) formed at different potentiostatic conditions (0.5, 1.0, 1.5 and 2.0 V vs SSE). A supporting electrolyte of 0.1 M H{sub 2}SO{sub 4} (pH 1) has been used to emulate acidic corrosive conditions for the growth of films with an n-type electronic character. A modification of the point defect model (PDM) accounting for the formation of molecular hydrogen (blistering damage) is used to fit the experimental EIS diagrams, and obtain the kinetic parameters that best describe the semiconductive behavior of the passive films. After this analysis, diffusivities in the order of 5.37 {+-} 1.6 x 10{sup -17} and 1.98 {+-} 1.4 x 10{sup -20} cm{sup 2} s{sup -1} were obtained for the oxygen (D{sub VO}{center_dot}{center_dot}) and hydroxyl vacancies (D{sub VOH}{center_dot}), respectively. These findings show the capabilities of the EIS and the physicochemical modeling to account for the formation of valve-metal oxide films on a different range of conditions.

  14. Advertising on social media

    Sumit Goyal

    2013-05-01

    Full Text Available This communication reports the latest trends of advertising on social media. Social media advertising means to gain traffic or attention of online users through social media sites. Today, when a user thinks about buying something, he first comes to the internet, searches for that product, compares its price with other competing brands and takes a decision, which one to buy. In this write-up, author has discussed many aspects concerning advertising through social media, viz., what is social media? What is the impact of social media on mainstream media, why to advertise on social media? and what should be the strategy for advertising on social media. The author is of the view that in the year 2013, $4 billion will be spent on social media advertising across the globe and social media industry will generate over 1,00,000 new jobs all around the world.

  15. The behaviour of polyaniline-coated PVC membrane based on 7, 16-didecyl-1, 4, 10, 13-tetraoxa-7, 16-diazacyclooctadecane for pH measurements in highly acidic media

    R Ansari; M Arvand; L Heydari

    2014-01-01

    Polyaniline(PANI) chemically coated on poly(vinyl chloride) (PVC) membrane based on a neutral carrier 7,16-didecyl-1,4,10,13-tetraoxa-7,16-diazacyclooctadecane (kryptofix 22 DD) as the active component has been developed for determination of pH values ranging from pH 0.1-1. The effect of experimental parameters such as membrane composition, nature and amount of plasticizer, lipophilic additives and thickness of PANI film on the potential response of the pH electrode was investigated. The electrode has an apparent Nernstian response slope of 54.5 ± 0.4 mV pH-1 (at 20°C). The equilibrium water content of the electrode was determined in pure water and NaCl solution (I = 0.1 mol Kg-1). The electrode had low electric resistance, good potential stability and reproducibility (±1.5 mV, = 10). It has a rapid potential response to changes of pH (15 s). The excellent performance in terms of linearity, stability and fast response makes this device suitable for pH measurements in highly acidic media.

  16. Strong Acid-Nonionic Surfactant Lyotropic Liquid-Crystalline Mesophases as Media for the Synthesis of Carbon Quantum Dots and Highly Proton Conducting Mesostructured Silica Thin Films and Monoliths.

    Olutaş, Elif B; Balcı, Fadime M; Dag, Ömer

    2015-09-22

    Lyotropic liquid-crystalline (LLC) materials are important in designing porous materials, and acids are as important in chemical synthesis. Combining these two important concepts will be highly beneficial to chemistry and material science. In this work, we show that a strong acid can be used as a solvent for the assembly of nonionic surfactants into various mesophases. Sulfuric acid (SA), 10-lauryl ether (C12E10), and a small amount of water form bicontinuous cubic (V1), 2D-hexagonal (H1), and micelle cubic (I1) mesophases with increasing SA/C12E10 mole ratio. A mixture of SA and C12E10 is fluidic but transforms to a highly ordered LLC mesophase by absorbing ambient water. The LLC mesophase displays high proton conductivity (1.5 to 19.0 mS/cm at room temperature) that increases with an increasing SA content up to 11 SA/C12E10 mole ratio, where the absorbed water is constant with respect to the SA amount but gradually increases from a 2.3 to 4.3 H2O/C12E10 mole ratio with increasing SA/C12E10 from 2 to 11, respectively. The mixture of SA and C12E10 slowly undergoes carbonization to produce carbon quantum dots (c-dots). The carbonization process can be controlled by simply controlling the water content of the media, and it can be almost halted by leaving the samples under ambient conditions, where the mixture slowly absorbs water to form photoluminescent c-dot-embedded mesophases. Over time the c-dots grow in size and increase in number, and the photoluminescence frequency gradually shifts to a lower frequency. The SA/C12E10 mesophase can also be used as a template to produce highly proton conducting mesostructured silica films and monoliths, as high as 19.3 mS/cm under ambient conditions. Aging the silica samples enhances the conductivity that can be even larger than for the LLC mesophase with the same amount of SA. The presence of silica has a positive effect on the proton conductivity of SA/C12E10 systems. PMID:26332603

  17. Media and Body Image

    ... Management Education & Events Advocacy For Patients About ACOG Media and Body Image Home For Patients Search FAQs Media and Body ... and Body Image TFAQ002, June 2016 PDF Format Media and Body Image Especially For Teens How can the media make ...

  18. Why Media Matter

    Locatis, Craig

    2007-01-01

    Whether media affect learning has been debated for decades. The discussion of media's effectiveness has raised questions about the usefulness of comparison studies, not only in assessing applications of technology but in other areas as well. Arguments that media do not affect learning are re-examined and issues concerning media effects on expert…

  19. Media Violence and Children.

    Groebel, Jo

    1998-01-01

    Presents the results of the UNESCO global study on media violence and children which was conducted between 1996 and 1997. Highlights include the role of the media, media heroes as role models, media violence and aggression, differences by gender, rural versus urban environments, the pervasiveness of television, and recommendations. (Author/LRW)

  20. The Media Mixer

    Vestergaard, Vitus; Mortensen, Christian Hviid

    2011-01-01

    throughout the Internet, most notably on web 2.0 sites like YouTube. The Media Museum has embraced the remix paradigm with the development of an interactive media experience centre called the Media Mixer. Here the museum users can produce, deconstruct, reconstruct and finally publish and share digital media...