Weighted oscillator strengths and lifetimes for the S IX and S X spectra

The weighted oscillator strengths (gf) and the lifetimes presented in this work were carried out in a multi configuration Hartree-Fock relativistic (HFR) approach. In this calculation, the electrostatic parameters were optimized by a least-squares procedure, in order to improve the adjustment to experimental energy levels. This method produces gf-values that are in better agreement with intensity observations and lifetime values that are closer to the experimental ones. In this work, we presented all the experimentally known electric dipole S IX and S X spectral lines.     

Unsteady axisymmetric stagnation flow on a circular cylinder

Unsteady, axisymmetric stagnation flow about a circular cylinderis examined when the far-field flow is a periodic function oftime with a fixed time average and an oscillatory part of prescribedamplitude and frequency. Solutions are computed for arbitraryvalues of the Reynolds number, quantifying the effects of surfacecurvature, and a frequency parameter based on the period ofthe far-field flow. It is found that solutions remain regularand periodic provided that the far-field amplitude lies belowa critical value. Above this value, solutions terminate in afinite-time singularity. The blow-up time is delayed by increasingthe curvature of the surface. These results are corroboratedby asymptotic predictions valid in the limits of small and largeamplitude and frequency. For large Reynolds number, the problemreduces to the two-dimensional stagnation-point flow againsta plane wall studied by previous authors.     

Lipase production by solid-state fermentation

The production of lipase by Penicillium simplicissimum in solid-state fermentation was studied using babassu cake as the basal medium. Tray-type and packed-bed bioreactors were employed. In the former, the influence of temperature; content of the medium, and medium supplementation with olive oil, sugarcane molasses, corn steep liquor, and yeast hydrolysate was studied. For all combinations of supplements, a temperature of 30°C, a moisture content of 70%, and a concentration of carbon source of 6.25% (m/m, dry basis) provided optimum conditions for lipase production. When used as single supplements olive oil and molasses also were able to provide high lipase activities (20 U/g). Using packed-bed bioreactors and molasses-supplemented medium, optimum conditions for enzyme production were air superficial velocities above 55 cm/min and temperatures below 28°C. The lower temperature optimum found for these reactors is probably related to radial heat gradient formation inside the packed bed. Maximum lipase activities obtained in these bioreactors (26.4 U/g) were 30% higher than in tray-type reactors.     

Recovery and Purity of High Molar Mass Bio-hyaluronic Acid Via Precipitation Strategies Modulated by pH and Sodium Chloride

Applied Biochemistry and Biotechnology - The effects of ethanol/broth proportions and the number of steps at varying pH in the presence or absence of sodium chloride (NaCl) were studied as...     

Liquid–Liquid Phase Equilibrium and Ion-Exchange Exploration for Aqueous Two-Phase Systems of ([C4mim]Cl + K2CO3 or K3C6H5O7 + water) at Different Temperatures

Journal of Solution Chemistry - Liquid–liquid equilibrium (LLE) data and phase diagrams for new aqueous two-phase systems (ATPSs) containing 1-butyl-3-methylimidazolium chloride...     

Karyotype characterization of Eurysternus caribaeus: the smallest diploid number among Scarabaeidae (Coleoptera: Scarabaeoidea)

Eurysternus caribaeus was analyzed cytologically by conventional chromosomal staining. The species presents a diploid number of 2n=8, chromosomes with two arms and an XY sex determining mechanism. This is the first karyotype described for the genus Eurysternus and the tribe Eurysternini, and is also the smallest diploid number observed in the family Scarabaeidae and superfamily Scarabaeoidea.     

Polyethylene glycol matrix reduces the rates of photochemical and thermal release of nitric oxide from S-nitroso-N-acetylcysteine

S -nitrosothiols have many biological activities and may act as nitric oxide (NO) carriers and donors, prolonging NO half-life in vivo. In spite of their great potential as therapeutic agents, most S -nitrosothiols are too unstable to isolate. We have shown that the S -nitroso adduct of N -acetylcysteine (SNAC) can be synthesized directly in aqueous and polyethylene glycol (PEG) 400 matrix by using a reactive gaseous (NO/O₂) mixture. Spectral monitoring of the S–N bond cleavage showed that SNAC, synthesized by this method, is relatively stable in nonbuf-fered aqueous solution at 25°C in the dark and that its stability is greatly increased in PEG matrix, resulting in a 28-fold decrease in its initial rate of thermal decomposition. Irradiation with UV light (λ= 333 nm) accelerated the rate of decomposition of SNAC to NO in both matrices, indicating that SNAC may find use for the photogeneration of NO. The quantum yield for SNAC decomposition decreased from 0.65 ± 0.15 in aqueous solution to 0.047 ± 0.005 in PEG 400 matrix. This increased stability in PEG matrix was assigned to a cage effect promoted by the PEG microenvironment that increases the rate of geminated radical pair recombination in the homolytic S–N bond cleavage process. This effect allowed for the storage of SNAC in PEG at −20°C in the dark for more than 10 weeks with negligible decomposition. Such stabilization may represent a viable option for the synthesis, storage and handling of S -nitrosothiol solutions for biomedical applications.     

Existence and asymptotic stability for evolution problems on manifolds with damping and source terms

One considers the nonlinear evolution equation with source and damping terms