890 resultados para SODIUM 40


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Field experiments were conducted over 3 years to study the effect of applying triazole and strobilurin fungicides on the bread-making quality of Malacca winter wheat. Averaged over all years the application of a fungicide programme increased yields, particularly when strobilurin fungicides were applied. Reductions in protein concentration, sulphur concentration, Hageberg failing number and loaf volumes also occurred as the amount of fungicide applied increased. However, there were no deleterious effects of fungicide application on sodium dodecyl sulphate (SDS) sedimentation volumes, N:S ratios or dough theology. Effects of fungicide application on bread-making quality were not product specific. Therefore, it appears that new mechanisms to explain strobilurin effects on bread-making quality do not need to be invoked. Where reductions in protein concentration did occur they could be compensated for by a late-season application of nitrogen either as granular ammonium nitrate at flag leaf emergence or foliar urea at anthesis. These applications, however, sometimes increased the N:S ratio of the extracted flour and failed to improve loaf volume. Multiple regression analysis revealed that main effects of year, flour protein concentration and N:S ratio could explain 93% of the variance in loaf volume caused by season, fungicide and nitrogen treatments. However, an equally good fit was achieved by just including sulphur concentration with year. (C) 2004 Elsevier Ltd. All rights reserved.

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Soymilks with sodium hexametaphosphate (SHMP) (0% to 1.2%) and calcium chloride (12.50, 18.75, and 25.00 mM Ca),were analyzed for total Ca, Ca ion concentration, pH, kinematic viscosity, particle diameter, and sediment after pasteurization. Higher added Ca led to significant (P <= 0.05) increases in Ca ion concentration and significant (P <= 0.05) decreases in pH. At certain levels of SHMP, higher concentrations of added Ca significantly increased (P <= 0.05) kinematic viscosity, particle diameter, and sediment. Increasing SHMP concentration reduced Ca ion concentration, particle diameter, and dry sediment content, but reduced kinematic viscosity of samples (P <= 0.05). Adding SHMP up to 0.7% influenced pH of soymilk in different ways, depending on the level of Ca addition. When the pH of Ca-fortified soymilk was adjusted to a higher level, ionic Ca decreased as pH increased. Ihere was a negative linear relationship between the logarithm of ionic Ca concentration and the adjusted pH of the soymilk. Ionic Ca appeared to be a good indicator of thermally induced sediment formation, with little sediment being produced if ionic Ca was maintained below 0.4 mM.

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The aim of this study is to investigate the mechanism responsible for the recovery of astaxanthin using Colloidal Gas Aphrons (CGA), which are surfactant stabilised microbubbles. The latter were produced using different surfactant solutions (Cetyl Trimethyl Ammonium Bromide (CTAB)-cationic, Sodium Dodecyl Sulfate (SDS)-anionic, TWEEN 60-non-ionic and mixtures of TWEEN 60-SPAN 80- non-ionic with varying hydrophobicity) at stirring speed 8000 rpm and stirring time 5 min. Experiments were carried out at varying pH and volumetric ratios of astaxanthin to CGA, and with two different astaxanthin standard suspensions: (i) astaxanthin dispersed in aqueous solutions and (ii) astaxanthin dispersed in ethanolic/aqueous solutions with different compositions of ethanol (20/80 (v/v) and 40/60 (v/v)). When astaxanthin is dispersed in aqueous solutions the separation seems to occur mainly by electrostatic interactions. Therefore the recoveries are higher in the case of the cationic surfactant when astaxanthin particles are strongly negatively charged, as shown by the zeta potential measurements. When ethanol is present, highest recoveries are achieved with CGA produced from the non-ionic surfactant, which indicates that, under these conditions, separation is driven mainly by hydrophobic interactions. In experiments with ethanolic/aqueous suspensions, when the hydrophobicity of the surfactant was increased by increasing volumes of SPAN 80, the CGA produced were less stable; thus higher recoveries of astaxanthin under conditions that favour hydrophobic interactions were not observed. (C) 2008 Elsevier B.V All rights reserved.

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Chronic fish oil intervention had been shown to have a positive impact on endothelial function. Although high-fat meals have often been associated with a loss of postprandial vascular reactivity, studies examining the effects of fish oil fatty acids on vascular function in the postprandial phase are limited. The aim of the present study was to examine the impact of the addition of fish oil fatty acids to a standard test meal on postprandial vascular reactivity. A total of 25 men received in a random order either a placebo oil meal (40 g of mixed fat; fatty acid profile representative of the U.K. diet) or a fish oil meal (31 g of mixed fat and 9 g of fish oil) on two occasions. Vascular reactivity was measured at baseline (0 h) and 4 h after the meal by laser Doppler iontophoresis, and blood samples were taken for the measurement of plasma lipids, total nitrite, glucose and insulin. eNOS (endothelial NO synthase) and NADPH oxidase gene expression were determined in endothelial cells after incubation with TRLs (triacylglycerol-rich lipoproteins) isolated from the plasma samples taken at 4 h. Compared with baseline, sodium nitroprusside (an endothelium-independent vasodilator)-induced reactivity (P = 0.024) and plasma nitrite levels (P = 0.001) were increased after the fish oil meal. In endothelial cells, postprandial TRLs isolated after the fish oil meal increased eNOS and decreased NADPH oxidase gene expression compared with TRLs isolated following the placebo oil meal (P <= 0.03). In conclusion, meal fatty acids appear to be an important determinant of vascular reactivity, with fish oils significantly improving postprandial endothelium-independent vasodilation.

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This paper presents the experimental results on the low temperature absorption and dispersion properties for a variety of frequently used infrared filter substrate materials. Index of refraction (n) and transmission spectra are presented for a range of temperatures 300-50 K for the Group IV materials silicon (Si) and germanium (Ge), and Group II-VI materials zinc selenide (ZnSe), zinc sulphide (ZnS) and cadmium telluride (CdTe). (C) 2003 Elsevier B.V. All rights reserved.

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We use atomistic molecular dynamics simulations to probe the effects of added sodium chloride (NaCl) and sodium salicylate (NaSal) salts on the spherical-to-threadlike micelle shape transition in aqueous solutions of cetyltrimethylammonium chloride (CTAC) surfactants. Long threadlike micelles are found to be unstable and break into spherical micelles at low concentrations or NaCl, but remain stable for 20 ns above a threshold value of [NaCl] approximate to 3.0 M, which is about 2.5 times larger than the experimental salt concentration at which the transition between spherical and rodlike micelles occurs. The chloride counterions associate weakly oil the surface of the CTAC micelles with the degree of counterion dissociation decreasing slightly with increasing [NaCl] on spherical micelles, but dropping significantly on the threadlike micelles tit high [NaCl]. This effect indicates that the electrolyte ions drive the micellar shape transition by screening the electrostatic repulsions between the micellar headgroups, The aromatic salicylate counterions, on the other hand, penetrate inside the micelle with their hydrophilic groups staying in the surfactant headgroup region and the hydrophobic groups partially embedded into the hydrophobic core of the micelle. The strong association of the salicylate ions with the surfactant headgroups leads to dense packing of the surfactant molecules, which effectively reduces the surface area per surfactant, and increases intramicellar ordering of the surfactant headgroups, favoring the formation of long threadlike micelles. Simulation predictions of the geometric and electrostatic properties of the spherical and threadlike micelles are in good agreement with experiments.

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The vacuum-deposited layer properties of materials of possible new use in infrared filters and coatings are described. These are comprehensively drawn from the II/VI, the heavy halide and the V/VI glass compounds, and are commercially available in all cases. Novel applications in coatings and filters are given for many of the materials.

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Multiple linear regression is used to diagnose the signal of the 11-yr solar cycle in zonal-mean zonal wind and temperature in the 40-yr ECMWF Re-Analysis (ERA-40) dataset. The results of previous studies are extended to 2008 using data from ECMWF operational analyses. This analysis confirms that the solar signal found in previous studies is distinct from that of volcanic aerosol forcing resulting from the eruptions of El Chichón and Mount Pinatubo, but it highlights the potential for confusion of the solar signal and lower-stratospheric temperature trends. A correction to an error that is present in previous results of Crooks and Gray, stemming from the use of a single daily analysis field rather than monthly averaged data, is also presented.

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The objective of this study was to determine the concentration of total selenium (Se) and proportions of total Se comprised as selenomethionine (SeMet) and selenocysteine (SeCys) in the tissues of female turkeys offered diets containing graded additions of selenized-enriched yeast (SY), or sodium selenite (SS). Oxidative stability and tissue glutathione peroxidase (GSH-Px) activity of breast and thigh muscle were assessed at 0 and 10 days post mortem. A total of 216 female turkey poults were enrolled in the study. A total of 24 birds were euthanized at the start of the study and samples of blood, breast, thigh, heart, liver, kidney and gizzard were collected for determination of total Se. Remaining birds were blocked by live weight and randomly allocated to one of four dietary treatments(n548 birds/treatment) that differed either in Se source (SY v. SS) or dose (Con [0.2 mg/kg total Se], SY-L and SS-L [0.3mg/kg total Se as SY and SS, respectively] and SY-H [0.45mg total Se/kg]). Following 42 and 84 days of treatment 24 birds per treatment were euthanized and samples of blood, breast, thigh, heart, liver, kidney and gizzard were retained for determination of total Se and the proportion of total Se comprised as SeMet or SeCys. Whole blood GSH-Px activity was determined at each time point. Tissue GSH-Px activity and thiobarbituric acid reactive substances were determined in breast and thigh tissue at the end of the study. There were responses (P,0.001) in all tissues to the graded addition of dietary Se, although rates of accumulation were highest in birds offered SY. There were notable differences between tissue types and treatments in the distribution of SeMet and SeCys, and the activity of tissue and erythrocyte GSH-Px (P,0.05). SeCys was the predominant form of Se in visceral tissue and SeMet the predominant form in breast tissue. SeCys contents were greater in thigh when compared with breast tissue. Muscle tissue GSH-Px activities mirrored SeCys contents. Despite treatment differences in tissue GSH-Px activity, there were no effects of treatment on any meat quality parameter.

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The complex [(C(NH2)3)3ZrOH(CO3)3·H2O]2 (A) has been shown by means of a single crystal X-ray diffraction study to contain [C(NH2)3]+ cations and dimeric anions of formulation [(ZrOH(CO3)3)2]6−. The anion is centrosymmetric with each metal being bonded to two bridging OH groups and three chelating CO2−3 ions. The Zr atoms are thus eight coordinate with a dodecahedral environments. The ZrO distances formed by the bridgng OH groups are shorter than those formed through zirconiu carbonate interactions. The non-bonded Zr…Zr distance is 3.47(2) Å. An infrared spectroscopic investigation of A provides data which support the findings of the crystallographic study. Likewise the complex Na6(ZrOH(CO2O4)3)2·7H2O (B) contains the anion [(ZrOH(C2O4)3)2]6−. This anion is structurally related to the anion in A as each Zr atom has an eight-coordinate dodecahedral environment being bonded to two bridging OH groups and three chelating oxalate ligands, but has no imposed crysallographic symmetry. The Zr…Zr non-bonded distance is 3.50(1) Å. The OZrO bridge angles are 69.7(4)° and A and 67.4(3)° in B.

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Hydrogels consisting of sodium alginate and N-isopropylacrylamide covalently crosslinked with N,N′-methylenebisacrylamide were prepared. The mixed-interpenetrated networks obtained were characterized using elemental analysis, Fourier transform infrared and Raman spectroscopy, swelling measurements and environmental scanning electron microscopy. The thermo- and pH-responsive properties of these hydrogels were evidenced by their swelling behaviour, which depended also on the amount of crosslinking agent and hydrogel composition.

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The synthesis of two new sodium perchlorate adducts (1:2 and 1:3) with copper(II) "ligand-complexes'' is reported. One adduct is trinuclear [(CuL(1))(2)NaClO(4)] (1) and the other is tetranuclear [(CuL(2))(3)Na]ClO(4)center dot EtOH (2). The ligands are the tetradentate di-Schiff base of 1,3-propanediamines and salicylaldehyde (H(2)L(1)) or 2-hydroxyacetophenone (H(2)L(2)). Both complexes have been characterized by X-ray single crystal structure analyses. In both structures, the sodium cation has a six-coordinate distorted octahedral environment being bonded to four oxygen atoms from two Schiff-base complexes in addition to a chelated perchlorate anion in 1 and to six oxygen atoms from three Schiff-base complexes in 2. We have carried out a DFT theoretical study (RI-B97-D/def2-SVP level of theory) to compute and compare the formation energies of 1:2 and 1:3 adducts. The DFT study reveals that the latter is more stabilized than the former. The X-ray crystal structure of 1 shows that the packing of the trinuclear unit is controlled by unconventional C-H center dot center dot center dot O H-bonds and Cu(2+)-pi non-covalent interactions. These interactions explain the formation of 1 which is a priori disfavored with respect to 2.

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Four new nickel(II) complexes, [Ni2L2(NO2)2]·CH2Cl2·C2H5OH, 2H2O (1), [Ni2L2(DMF)2(m-NO2)]ClO4·DMF (2a), [Ni2L2(DMF)2(m-NO2)]ClO4 (2b) and [Ni3L¢2(m3-NO2)2(CH2Cl2)]n·1.5H2O (3) where HL = 2-[(3-amino-propylimino)-methyl]-phenol, H2L¢ = 2-({3-[(2-hydroxy-benzylidene)-amino]-propylimino}-methyl)-phenol and DMF = N,N-dimethylformamide, have been synthesized starting with the precursor complex [NiL2]·2H2O, nickel(II) perchlorate and sodium nitrite and characterized structurally and magnetically. The structural analyses reveal that in all the complexes, NiII ions possess a distorted octahedral geometry. Complex 1 is a dinuclear di-m2-phenoxo bridged species in which nitrite ion acts as chelating co-ligand. Complexes 2a and 2b also consist of dinuclear entities, but in these two compounds a cis-(m-nitrito-1kO:2kN) bridge is present in addition to the di-m2-phenoxo bridge. The molecular structures of 2a and 2b are equivalent; they differ only in that 2a contains an additional solvated DMF molecule. Complex 3 is formed by ligand rearrangement and is a one-dimensional polymer in which double phenoxo as well as m-nitrito-1kO:2kN bridged trinuclear units are linked through a very rare m3-nitrito-1kO:2kN:3kO¢ bridge. Analysis of variable-temperature magnetic susceptibility data indicates that there is a global weak antiferromagnetic interaction between the nickel(II) ions in four complexes, with exchange parameters J of -5.26, -11.45, -10.66 and -5.99 cm-1 for 1, 2a, 2b and 3, respectively

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At the end of the 20th century, we can look back on a spectacular development of numerical weather prediction, which has, practically uninterrupted, been going on since the middle of the century. High-resolution predictions for more than a week ahead for any part of the globe are now routinely produced and anyone with an Internet connection can access many of these forecasts for anywhere in the world. Extended predictions for several seasons ahead are also being done — the latest El Niño event in 1997/1998 is an example of such a successful prediction. The great achievement is due to a number of factors including the progress in computational technology and the establishment of global observing systems, combined with a systematic research program with an overall strategy towards building comprehensive prediction systems for climate and weather. In this article, I will discuss the different evolutionary steps in this development and the way new scientific ideas have contributed to efficiently explore the computing power and in using observations from new types of observing systems. Weather prediction is not an exact science due to unavoidable errors in initial data and in the models. To quantify the reliability of a forecast is therefore essential and probably more so the longer the forecasts are. Ensemble prediction is thus a new and important concept in weather and climate prediction, which I believe will become a routine aspect of weather prediction in the future. The limit between weather and climate prediction is becoming more and more diffuse and in the final part of this article I will outline the way I think development may proceed in the future.

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BACKGROUND: Dextran-40 is effective in reducing postoperative Doppler-detectable embolization in patients undergoing carotid endarterectomy (CEA). Dextrans are thought to have antithrombotic and antiplatelet effects. The mode of action is unclear. In rats, dextran blocks uptake of tissue plasminogen activator (tPA) by mannose-binding receptors. Because this would have the effect of enhancing endogenous fibrinolysis, we explored this effect of dextran-40 on fibrinolysis in man. METHODS: Twenty patients undergoing endovascular stenting for abdominal aortic aneurysm were randomized to receive 100 mL of 10% dextran-40 or saline, over 1 hour, during their operation in addition to heparin. Blood samples were taken preoperatively, intraoperatively (immediately after operative procedure), and 24 hours postoperatively. Thrombi were formed in a Chandler loop and used to assess endogenous fibrinolysis over 24 hours, measured as the fall in thrombus weight, and the release of fluorescently labelled fibrinogen from the thrombus. Plasma samples were analyzed for markers of fibrinolysis; plasmin-antiplasmin (PAP), PAI-1, and t-PA, and for functional von Willebrand factor (vWF). Platelet response to thrombin and other agonists was measured by flow cytometry. RESULTS: Thrombi formed ex vivo from the intraoperative blood samples from the dextran-treated patients exhibited significantly greater fibrinolysis vs preoperative samples, seen both as a significantly greater percentage reduction in thrombus weight (from 34.7% to 70.6% reduction) and as an 175% increase in the release of fluorescence (P < .05). Fibrinolysis returned to baseline levels the next day. No change was seen in the saline-treated group. Plasma levels of PAP and PAI-1 increased significantly postoperatively in the dextran-treated group vs the saline group (P < .05). The postoperative level of functional VWF was significantly lower in the dextran-treated group vs controls. A specific reduction occurred in the platelet response to thrombin, but not to other agonists, in the intraoperative samples from the dextran-treated group (11.1% vs 37.1%; P = .022), which was not seen in the controls. CONCLUSIONS: These data are consistent with a rise in plasmin due to dextran blockade of tPA uptake in vivo, leading to enhanced fibrinolysis, cleavage of vWF and of the platelet protease-activated receptor-1 (PAR-1) thrombin receptor. This suggests that dextran exerts a combined therapeutic effect, enhancing endogenous fibrinolysis, whilst also reducing platelet adhesion to vWF and platelet activation by thrombin. The proven antithrombotic efficacy of low-dose dextran in carotid surgery may be applicable to wider therapeutic use.