901 resultados para Poly(styrene-b-4-vinyl pyridine)


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Accumulation of neutr ophils releasing proteolytic enzymes and free radicals induceprogressive lung tissue destruction in CF. Among several hfflammatory mediatorsimplicated in this process, leukotriene B 4 (LTB4) product of arachidonic (AA;20:4n 6) omega 6 polytmsaturated fatty acid (PUFA) plays an important role.Various anti inflammatory strategies including dietary supplementation of omega 3PUFA, known to favor the synthesis of less active leukotriene B 5 (LTBs), have beeninvestigated. To further explore this nutritional approach, biological effects of anomega 3 PUFA oral supplementation (n 3 OS) were measured in 17 CF patients haa prospective, randomized, double blind, crossover study. CF patients (mean age:18 + 9 years, FEVI: 66 + 29 %) received a dietary supplementation enriched, or not,ha omega 3 PUFA during a 2 x 6 months period. A modification in neutrophilmembrane PUFA composition was observed under n 3 OS with an increase in EPA(20:5n 3) PUFA (from 0.66 ± 0.56 to 1.60 ± 0.61 ~tmol %, P< 0.01). The LTB jLTB 5ratio was decreased (from 72 + 27 to 24 + 7, P< 0.C~31), in CF patients taking n 3OS. However, n 3 OS supplementation did neither affect the internalization of bothIL 8 receptors following IL 8 exposure, nor IL 8 induced neutrophil chemotaxis.Our results show that n 3 PUFA are absorbed and incorporated in neutrophilmembrmae. The consecutive decrease ha LTBjLTB 5 ratio suggests that, ha theseconditions, neutr ophils may produce less toxic mediators from the AA pathway. Thepotential clinical benefit for CF patients still needs to be assessed with furtherstudies of longer duration and including more patients.

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Se presentan los resultados de la prospección de recursos pelágicos costeros y demersales costeros 9611-12, a bordo de la EE Huamanga entre Callao y Puerto Pizarro. La metodología empleada consistió en un rastreo hidroacústico complementado con lances de comprobación, así como una prospección costera con arrastre de fondo en zonas donde la eco abundancia del rastreo acústico detectó concentraciones. Los recursos pelágicos costeros se determinaron de Huacho a Puerto Pizarro entre 0 a 20 mn de la costa. Los recursos demersales costeros se encontraron distribuidos en toda el área evaluada, fuertemente concentrados entre Punta Falsa y Puerto Pizarro. Cabrillas, mojarrillas y rayas, tuvieron mayores índices de abundancia en la subárea A (03° a 04° S); cachema, suco y lenguado destacaron en la subárea B (4° a 5°S). Por su alta frecuencia en las capturas, se han determinado las condiciones sexuales de los recursos cabrilla, cachema, lorna, suco y vocador, presentando un comportamiento normal para la época.

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El informe corresponde a la evaluación de la merluza peruana por el método de área barrida, desde Puerto Pizarro al sur de Punta Malabrigo, entre el 4 al 18 de junio 2003. Se evaluó la recuperación del recurso después de casi nueve meses de suspensión de pesca comercial. Los resultados más importantes fueron: (1) Incremento de la densidad poblacional a profundidades entre 100 y 200 m en las subáreas B (4-5°S, con 36,53 t/mn2) y D (6-7°S, con 118 t/mn2); (2) La biomasa total llegó a 168.000 t, cifra mayor a las del verano 2003 y otoño 2002; (3) Incremento del stock desovante hasta 77.000 t, pero menor a la cantidad mínima requerida para garantizar su renovación y sustentabilidad en el tiempo; (4) La estructura poblacional conformada por ejemplares de 9 a 60 cm de LT, tamaños modales en 12, 19 y 29 cm de LT, y edades de 0 a 7 años con predominio de ejemplares jóvenes de uno (69%) y dos años de edad (24%), que evidenció buen reclutamiento en otoño.

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Se analiza la situación de los principales recursos demersales durante la realización del Crucero 0305-06 a bordo del BIC Olaya, del 20 de mayo al 18 de junio 2003, en el área de Punta Malabrigo a Puerto Pizarro entre las isobatas de 20 a 200 bz de profundidad. Las especies acompañantes de la merluza peruana, más importantes en las capturas, y en orden de importancia por su mayor ocurrencia y tonelaje fueron: Ctenosciaena peruviana (bereche con barbo), Peprilus medius (chiri), Cynoscion analis (cachema), Prionotus stephanophrys (falso volador), Hippoglossina macrops (lenguado ojón). La concentración del oxígeno disuelto en el fondo favoreció la presencia de los recursos demersales acompañantes de la merluza. Estas especies con bajas densidades se distribuyeron en forma muy dispersa, el lenguado ojón fue el recurso que tuvo amplia distribución. Las mayores abundancias relativas se encontraron principalmente en las subáreas A (3°23’–4°S) y B (4°-5°S) y en los estratos de profundidad I (20–50 bz) y II (50–100 bz), también se dan apreciaciones sobre las estructuras de tallas y la madurez gonadal de algunas especies.

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Au fol. 5, miniature dans laquelle l'auteur est représenté offrant son ouvrage à Louise de Savoie. Ce volume, pour l'ornementation comme pour l'écriture, semble être de la même main que celui qui porte le n° 5715. Elle a été composée sur la demande de Louise de Savoie, ainsi que l'auteur le déclare dans sa dédicace (fol. 5). Elle commence (fol. 1) avant cette dédicace par : « Pour plus facillement entendre le contenu en ce present livre, au commencement d'iceluy ay mys ceste presente genealogie de la maison de Bourbon. Monsieur sainct Loys, roy de France... » et finit (fol. 30) par : «... esquelz escriptz toute foy doit estre adjoustée ». La seconde partie de l'ouvrage (fol. 23-30) est consacrée à saint Louis : « Probation que monseigneur sainct Loys ne destruisit point le royaume pour le sainct voyaige qu'il feist oultre mer ». L'auteur pour justifier saint Louis d'avoir ruiné le royaume pour le payement de sa rançon, lors de sa première croisade, énumère (fol. 23-24) les reliques acquises par ce roi, donne, en passant (fol. 24-25), les noms des « roys de France qui ont été en Terre saincte », indique (fol. 25-26) à combien monta la rançon de saint Louis, et montre qu'elle ne fut pas disproportionnée eu égard au temps et à la qualité du prisonnier du Soudan ; passe ensuite en revue (fol. 26-27) les églises et hôpitaux fondés après le payement de cette rançon par le saint roi, sans avoir recours à aucune taille, aide ni subside ; montre (fol. 27-28) que saint Louis ne fit jamais de monnaie de cuir et que c'est longtemps après son décès que les gabelles (fol. 28-29) furent établies. En dernier lieu, il parle (fol. 29-30) de la canonisation de saint Louis, proclamée en 1297 par les soins et aux frais de Philippe le Bel son petit-fils. Miniature, encadrement, lettres ornées.

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Au fol. 5, miniature dans laquelle l'auteur est représenté offrant son ouvrage à Louise de Savoie. Ce volume, pour l'ornementation comme pour l'écriture, semble être de la même main que celui qui porte le n° 5715. Elle a été composée sur la demande de Louise de Savoie, ainsi que l'auteur le déclare dans sa dédicace (fol. 5). Elle commence (fol. 1) avant cette dédicace par : « Pour plus facillement entendre le contenu en ce present livre, au commencement d'iceluy ay mys ceste presente genealogie de la maison de Bourbon. Monsieur sainct Loys, roy de France... » et finit (fol. 30) par : «... esquelz escriptz toute foy doit estre adjoustée ». La seconde partie de l'ouvrage (fol. 23-30) est consacrée à saint Louis : « Probation que monseigneur sainct Loys ne destruisit point le royaume pour le sainct voyaige qu'il feist oultre mer ». L'auteur pour justifier saint Louis d'avoir ruiné le royaume pour le payement de sa rançon, lors de sa première croisade, énumère (fol. 23-24) les reliques acquises par ce roi, donne, en passant (fol. 24-25), les noms des « roys de France qui ont été en Terre saincte », indique (fol. 25-26) à combien monta la rançon de saint Louis, et montre qu'elle ne fut pas disproportionnée eu égard au temps et à la qualité du prisonnier du Soudan ; passe ensuite en revue (fol. 26-27) les églises et hôpitaux fondés après le payement de cette rançon par le saint roi, sans avoir recours à aucune taille, aide ni subside ; montre (fol. 27-28) que saint Louis ne fit jamais de monnaie de cuir et que c'est longtemps après son décès que les gabelles (fol. 28-29) furent établies. En dernier lieu, il parle (fol. 29-30) de la canonisation de saint Louis, proclamée en 1297 par les soins et aux frais de Philippe le Bel son petit-fils. Miniature, encadrement, lettres ornées.

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The main sources of coarse aggregate for secondary slip form paving in Southwest Iowa exhibit undesirable "D" cracking. "D" cracking is a discoloration of the concrete caused by fine, hairline cracks. These cracks are caused by the freezing and thawing of moisture inside the coarse aggregate. The cracks are often hour glass shaped, are parallel to each other, and occur along saw joints. The B-4, a typical secondary mix, utilizes 50% fine aggregate and 50% coarse aggregate. It has been proposed that a concrete mix with less coarse aggregate and more fine aggregate might impede this type of deterioration. The Nebraska Standard 47B Mix, a 70% fine aggregate, and 30% coarse aggregate mix, as used by Nebraska Department of Roads produces concrete with ultimate strengths in excess of 4500 psi but because of the higher cost of cement (it is a six bag per cubic yard mix) is not competitive with our present secondary mixes. The sands of Southwest Iowa generally have poorer mortar strengths than the average Iowa Sand. Class V Aggregate also found in Southwest Iowa has a coarser sand fraction, therefore it has a better mortar strength, but exhibits an acidic reaction and therefore must be·used with limestone. This illustrates the need to find a mix for use in Southwest Iowa that possesses adequate strength and satisfactory durability at a low cost. The purpose of this study is to determine a concrete mix with an acceptable cement content which will produce physical properties similar to that of our present secondary paving mixes.

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Aims: Plasma concentrations of imatinib differ largely between patients despite same dosage, owing to large inter-individual variability in pharmacokinetic (PK) parameters. As the drug concentration at the end of the dosage interval (Cmin) correlates with treatment response and tolerability, monitoring of Cmin is suggested for therapeutic drug monitoring (TDM) of imatinib. Due to logistic difficulties, random sampling during the dosage interval is however often performed in clinical practice, thus rendering the respective results not informative regarding Cmin values.Objectives: (I) To extrapolate randomly measured imatinib concentrations to more informative Cmin using classical Bayesian forecasting. (II) To extend the classical Bayesian method to account for correlation between PK parameters. (III) To evaluate the predictive performance of both methods.Methods: 31 paired blood samples (random and trough levels) were obtained from 19 cancer patients under imatinib. Two Bayesian maximum a posteriori (MAP) methods were implemented: (A) a classical method ignoring correlation between PK parameters, and (B) an extended one accounting for correlation. Both methods were applied to estimate individual PK parameters, conditional on random observations and covariate-adjusted priors from a population PK model. The PK parameter estimates were used to calculate trough levels. Relative prediction errors (PE) were analyzed to evaluate accuracy (one-sample t-test) and to compare precision between the methods (F-test to compare variances).Results: Both Bayesian MAP methods allowed non-biased predictions of individual Cmin compared to observations: (A) - 7% mean PE (CI95% - 18 to 4 %, p = 0.15) and (B) - 4% mean PE (CI95% - 18 to 10 %, p = 0.69). Relative standard deviations of actual observations from predictions were 22% (A) and 30% (B), i.e. comparable to the intraindividual variability reported. Precision was not improved by taking into account correlation between PK parameters (p = 0.22).Conclusion: Clinical interpretation of randomly measured imatinib concentrations can be assisted by Bayesian extrapolation to maximum likelihood Cmin. Classical Bayesian estimation can be applied for TDM without the need to include correlation between PK parameters. Both methods could be adapted in the future to evaluate other individual pharmacokinetic measures correlated to clinical outcomes, such as area under the curve(AUC).

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In this thesis, the sorption and elastic properties of the cation-exchange resins were studied to explain the liquid chromatographic separation of carbohydrates. Na+, Ca2+ and La3+ form strong poly(styrene-co-divinylbenzene) (SCE) as well as Na+ and Ca2+ form weak acrylic (WCE) cation-exchange resins at different cross-link densities were treated within this work. The focus was on the effects of water-alcohol mixtures, mostly aqueous ethanol, and that of the carbohydrates. The carbohydrates examined were rhamnose, xylose, glucose, fructose, arabinose, sucrose, xylitol and sorbitol. In addition to linear chromatographic conditions, non-linear conditions more typical for industrial applications were studied. Both experimental and modeling aspectswere covered. The aqueous alcohol sorption on the cation-exchangers were experimentally determined and theoretically calculated. The sorption model includes elastic parameters, which were obtained from sorption data combined with elasticity measurements. As hydrophilic materials cation-exchangers are water selective and shrink when an organic solvent is added. At a certain deswelling degree the elastic resins go through glass transition and become as glass-like material. Theincreasing cross-link level and the valence of the counterion decrease the sorption of solvent components in the water-rich solutions. The cross-linkage or thecounterions have less effect on the water selectivity than the resin type or the used alcohol. The amount of water sorbed is higher in the WCE resin and, moreover, the WCE resin is more water selective than the corresponding SCE resin. Theincreased aliphatic part of lower alcohols tend to increase the water selectivity, i.e. the resins are more water selective in 2-propanol than in ethanol solutions. Both the sorption behavior of carbohydrates and the sorption differences between carbohydrates are considerably affected by the eluent composition and theresin characteristics. The carbohydrate sorption was experimentally examined and modeled. In all cases, sorption and moreover the separation of carbohydrates are dominated by three phenomena: partition, ligand exchange and size exclusion. The sorption of hydrophilic carbohydrates increases when alcohol is added into the eluent or when carbohydrate is able to form coordination complexes with the counterions, especially with multivalent counterions. Decreasing polarity of the eluent enhances the complex stability. Size exclusion effect is more prominent when the resin becomes tighter or carbohydrate size increases. On the other hand,the elution volumes between different sized carbohydrates decreases with the decreasing polarity of the eluent. The chromatographic separation of carbohydrateswas modeled, using rhamnose and xylose as target molecules. The thermodynamic sorption model was successfully implemented in the rate-based column model. The experimental chromatographic data were fitted by using only one adjustable parameter. In addition to the fitted data also simulated data were generated and utilized in explaining the effect of the eluent composition and of the resin characteristics on the carbohydrate separation.

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Dynamic behavior of bothisothermal and non-isothermal single-column chromatographic reactors with an ion-exchange resin as the stationary phase was investigated. The reactor performance was interpreted by using results obtained when studying the effect of the resin properties on the equilibrium and kinetic phenomena occurring simultaneously in the reactor. Mathematical models were derived for each phenomenon and combined to simulate the chromatographic reactor. The phenomena studied includes phase equilibria in multicomponent liquid mixture¿ion-exchange resin systems, chemicalequilibrium in the presence of a resin catalyst, diffusion of liquids in gel-type and macroporous resins, and chemical reaction kinetics. Above all, attention was paid to the swelling behavior of the resins and how it affects the kinetic phenomena. Several poly(styrene-co-divinylbenzene) resins with different cross-link densities and internal porosities were used. Esterification of acetic acid with ethanol to produce ethyl acetate and water was used as a model reaction system. Choosing an ion-exchange resin with a low cross-link density is beneficial inthe case of the present reaction system: the amount of ethyl acetate as well the ethyl acetate to water mole ratio in the effluent stream increase with decreasing cross-link density. The enhanced performance of the reactor is mainly attributed to increasing reaction rate, which in turn originates from the phase equilibrium behavior of the system. Also mass transfer considerations favor the use ofresins with low cross-link density. The diffusion coefficients of liquids in the gel-type ion-exchange resins were found to fall rapidly when the extent of swelling became low. Glass transition of the polymer was not found to significantlyretard the diffusion in sulfonated PS¿DVB ion-exchange resins. It was also shown that non-isothermal operation of a chromatographic reactor could be used to significantly enhance the reactor performance. In the case of the exothermic modelreaction system and a near-adiabatic column, a positive thermal wave (higher temperature than in the initial state) was found to travel together with the reactive front. This further increased the conversion of the reactants. Diffusion-induced volume changes of the ion-exchange resins were studied in a flow-through cell. It was shown that describing the swelling and shrinking kinetics of the particles calls for a mass transfer model that explicitly includes the limited expansibility of the polymer network. A good description of the process was obtained by combining the generalized Maxwell-Stefan approach and an activity model that was derived from the thermodynamics of polymer solutions and gels. The swelling pressure in the resin phase was evaluated by using a non-Gaussian expression forthe polymer chain length distribution. Dimensional changes of the resin particles necessitate the use of non-standard mathematical tools for dynamic simulations. A transformed coordinate system, where the mass of the polymer was used as a spatial variable, was applied when simulating the chromatographic reactor columns as well as the swelling and shrinking kinetics of the resin particles. Shrinking of the particles in a column leads to formation of dead volume on top of the resin bed. In ordinary Eulerian coordinates, this results in a moving discontinuity that in turn causes numerical difficulties in the solution of the PDE system. The motion of the discontinuity was eliminated by spanning two calculation grids in the column that overlapped at the top of the resin bed. The reactive and non-reactive phase equilibrium data were correlated with a model derived from thethermodynamics of polymer solution and gels. The thermodynamic approach used inthis work is best suited at high degrees of swelling because the polymer matrixmay be in the glassy state when the extent of swelling is low.

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A computational quantum chemistry experiment is described on the determination of the most reactive atom in a molecule for a reaction. The reaction studied was the S N2 of 4-(dimethylamino)pyridine and methyl iodide. Several indexes (HOMO coefficent, (c), charges, (q), nucleophilic softness, (s+), and Fukui index, (f+)) were employed to verify which correctly describe what nitrogen will react. The calculations were made by AM1 and HF/STO-3G methods. The correct reactivity order is only reproduced by s+ and f+. The lack of agreement of FMO based indexes was discussed.

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In this work we describe the processing of poly(styrene sulphonate) films (PSS) doped with neodymium (Nd). Optical density measurements in the UV-Vis-NIR region show the typical bands observed for neodymium chloride (NdCl3) in solution. In the case of films, the intensity ratio between the peaks at 800 nm (4I9/2 -> 4F5/2 + ²H7/2) and 580 nm (4I9/2 -> 4G5/2 + ²G7/2) is equal to 0.83. Infrared spectra present an enhancement in the absorption region of aromatic rings. Site selective luminescence spectroscopy shows that the incorporation of Nd introduces a hipsochromic shift and a line shape definition in UV luminescence compared to PSS film, decreasing the interaction between aromatic groups. In addition, the film exhibits an intense radiative transition at 1061 nm (4F3/2->4I11/2), comparable to the one present in crystalline materials doped with Nd.

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Five compounds, 2-hexyl-3-methyl-butanodioic acid (1), cytochalasin D (2), 7-dechlorogriseofulvin (3), cytochalasin B (4) and griseofulvin (5), have been isolated from the endophytic fungus Xylaria sp., and their structures were elucidated on the basis of spectroscopic data. In the bioautography assay against Cladosporium cladosporioides and Cladosporium sphaerospermum, compounds 1 and 2 were found to be active while compounds 3, 4 and 5 did not show antifungal activity.