995 resultados para 6-Phosphofructo-1-kinase


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The thermo-solvatochrornic behaviors of 2,6-diphenyl-4-(2,4,6-triphenylpyridinium-1-yl) phenolate, RB; 2,6-dichloro-4-(2,4,6-triphenyloyridinium-1-yl) phenolate, WB; 2,6-dibromo-4-[(E)-2-(1-methylpyridinium-4-yl)ethenyl] phenolate, MePMBr(2); 2,6-dibromo-4-[(E)-2-(1-n-octylpyridinium-4-yl)ethenyl] phenolate, OcPMBr(2), have been investigated in binary mixtures of the ionic liquid, IL, 1-(1-butyl)-3-methylimidazolium tetrafluorborate, [BuMeIm][BF(4)], and water (W), in the temperature range from 10 to 60 degrees C. Plots of the empirical solvent polarities, ET (probe) in kcal mol(-1), versus the mole fraction of water in the binary mixture, chi(w) showed nonlinear, i.e., nonideal behavior. Solvation by these IL-W mixtures shows the following similarities to that by aqueous aliphatic alcohols: The same solvation model can be conveniently employed to treat the data obtained; it is based on the presence in the system-bulk medium and probe solvation shell of IL, W, and the ""complex"" solvent 1:1 IL-W. The origin of the nonideal solvation behavior appears to be the same, preferential solvation of the probe, in particular by the complex solvent. The strength of association of the IL-W complex, and the polarity of the IL are situated between the corresponding values of aqueous methanol and aqueous ethanol. Temperature increase causes a gradual desolvation of all probes employed. A difference between solvation by IL-W and aqueous alcohols is that probe-solvent hydrophobic interactions appear to play a minor role in case of the former mixture, probably because solvation is dominated by hydrogen-bonding and Coulombic interactions between the ions of the IL and the zwitterionic probes.

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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The influence of moderate physical training on serum growth hormone (GH), insulin-like growth factor -1 (IGF-1) and binding protein ( IGFBP-3) in experimental diabetic rats was investigated. Male Wistar rats were divided into 4 groups, sedentary control (SC), trained control (TC), sedentary diabetic (SD) and trained diabetic (TD). Experimental diabetes was induced of Alloxan (35mg/b.w.) the training program consisted by swimming 5 days/week, 1 h/day, supporting a load of 2.5% b.w., during 6 weeks. Then, the rats were sacrificed and blood was collected for determinations of serum glucose, insulin, GH, IGF-1 and IGFBP-3. Samples of liver were used to evaluate glycogen, protein and DNA contents. The results were analyzed by ANOVA, and Bonferroni test and the significance level was set at 2.5%. Diabetes decreased serum GH, IGF-1, IGFBP-3 and liver glycogen stores in SD group. Physical training promoted increase in serum IGF-1 in both TC and TD groups (SC=82 +/- 15; TC= 1 03 +/- 13; SD=77 +/- 16; TD= 112 +/- 29 ng/ml) and liver glycogen store in TD group when compared to SD (SC=5.2 +/- 1.2; TC= 6.2 +/- 1; SD=2 +/- 0.5; TD=5 +/- 1.8 mg/100mg). Therefore, physical training contributes to the increase in liver glycogen content and to rise of insulin-like growth factor level in diabetic rats. It was concluded that moderate physical training promotes important adaptations related to GH-IGF-1 axis in diabetic organisms.

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We present a measurement of the top quark pair production cross section in p (p) over bar collisions at root s=1.96 TeV utilizing 425 pb(-1) of data collected with the D0 detector at the Fermilab Tevatron Collider. We consider the final state of the top quark pair containing one high-p(T) electron or muon and at least four jets. We exploit specific kinematic features of t (t) over bar events to extract the cross section. For a top quark mass of 175 GeV, we measure sigma(t (t) over bar)=6.4(-1.2)(+1.3)(stat)+/- 0.7(syst)+/- 0.4(lum) pb, in good agreement with the standard model prediction.

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We present a measurement of the top quark pair (t (t) over bar) production cross section (sigma(t (t) over bar)) in pp collisions at a center-of-mass energy of 1.96 TeV using 230 pb(-1) of data collected by the DO detector at the Fermilab Tevatron Collider. We select events with one charged lepton (electron or muon), large missing transverse energy, and at least four jets, and extract the t (t) over bar content of the sample based on the kinematic characteristics of the events. For a top quark mass of 175 GeV, we measure sigma(t (t) over bar) 6.7(-1.3)(+1.4)(stat)(-1.1)(+1.6)(syst) +/- 0.4(lumi) pb, in good agreement with the standard model prediction. (c) 2005 Elsevier B.V. All rights reserved.

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The WW gamma triple gauge boson coupling parameters are studied using p (p) over bar -> l nu gamma + X(l = e, mu) events at root s = 1.96 TeV. The data were collected with the D0 detector from an integrated luminosity of 162 pb(-1) delivered by the Fermilab Tevatron Collider. The cross section times branching fraction for p (p) over bar -> W(gamma) + X -> l nu gamma + X with E-T(gamma) > 8 GeV and Delta R-l gamma > 0.7 is 14.8 +/- 1.6(stat) +/- 1.0(syst) +/- 1.0(lum) pb. The one-dimensional 95% confidence level limits on anomalous couplings are -0.88 < Delta kappa(gamma) < 0.96 and -0.20 < lambda(gamma) < 0.20.

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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Both the parity-breaking and parity-invariant parts of the effective action for the gauge field in QED 3 with massive fermions at finite temperature are obtained exactly. This is feasible because we use a particular configuration of the background gauge field, namely a constant magnetic field and a time-dependent time component of the background gauge field. Our results allow us to compute exactly physically interesting quantities such as the induced charge density and fermion condensate whose dependence on the temperature, fermion mass and gauge field is discussed. ©1999 The American Physical Society.

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The WWγ triple gauge boson coupling parameters are studied using pp̄rarr; νγ+X(=e,μ) events at s=1.96 TeV. The data were collected with the D0 detector from an integrated luminosity of 162pb-1 delivered by the Fermilab Tevatron Collider. The cross section times branching fraction for pp̄→W(γ)+X→ νγ+X with ETγ>8 GeV and ΔR γ> 0.7 is 14.8±1.6(stat)±1.0(syst) ±1.0(lum)pb. The one-dimensional 95% confidence level limits on anomalous couplings are -0.88<Δκγ<0.96 and -0. 20<λγ<0.20. © 2005 The American Physical Society.

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We present the first search for new phenomena in Zγ final states with large missing transverse energy using data corresponding to an integrated luminosity of 6.2fb -1 collected with the D0 experiment in pp̄ collisions at √s=1.96TeV. This signature is predicted in gauge-mediated supersymmetry-breaking models, where the lightest neutralino χ 10 is the next-to-lightest supersymmetric particle and is produced in pairs, possibly through decay from heavier supersymmetric particles. The χ 10 can decay either to a Z boson or a photon and an associated gravitino that escapes detection. We exclude this model at the 95% C.L. for supersymmetry-breaking scales of Λ<87TeV. © 2012 American Physical Society.

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A biomimetic sensor based on a carbon paste electrode modified with the nickel(II) 1,4,8,11,15,18,22,25-octabutoxy-29H,31H-phthalocyanine complex was developed as a reliable alternative technique for the sensitive and selective analysis of the herbicide diuron in environmental media. The sensor was evaluated using cyclic voltammetry and amperometric techniques. The best amperometric responses were obtained at 750 mV vs. Ag/AgCl (KClsat), using 0.1 mol L-1 phosphate buffer solution at pH 8.0. Under these conditions, the sensor showed a linear response for diuron concentrations between 9.9 × 10-6 and 1.5 × 10-4 mol L -1, a sensitivity of 22817 (±261) μA L mol-1, and detection and quantification limits of 6.14 × 10-6 and 2 × 10-5 mol L-1, respectively. The presence of the nickel complex in the carbon paste improved selectivity, stability, and sensitivity (which increased 700%), compared to unmodified paste. The applicability of the sensor was demonstrated using enriched environmental samples (river water and soil). © 2012 Elsevier B.V. All rights reserved.

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A disposable pencil graphite electrode modified with dsDNA was used in combination with square wave voltammetry in order to evaluate the interaction of DNA with the textile dyes Disperse Orange 1 (DO1) and Disperse Red 1 (DR1), and with the products of their electrolysis. Significant changes in the characteristic oxidation peaks of the guanine and adenine moieties of immobilized dsDNA were observed after incubation of the modified electrode for 180 s in solutions of the dyes in their original forms. The same was observed using the electrolysis products obtained by oxidation and reduction conversions. The oxidation peak currents of the guanine and adenine moieties decreased when the concentrations of DO1 and DR1 were increased up to 5.0 × 10 -6 and 1.0 × 10-6 mol L-1, respectively; the signal decreases were more pronounced after interaction with the oxidized dyes, compared to the reduced compounds. The interactions between DNA and DO1, DR1, and the electrolyzed dyes were further investigated by UV-vis spectrophotometry in solution, and different effects such as hypochromism and hyperchromism were observed in the resulting DNA spectra. The investigated interactions showed clear evidence of changes in the DNA structure, and suggested a predominant intercalation mode leading to damage in the biomolecule. © 2013 Elsevier B.V.