Enzymatic hydrolysis of steam-exploded and ethanol organosolv-pretreated douglas-fir by novel and commercial fungal cellulases

Softwood residues are the most abundant feedstock available for bioconversion in many northern countries. However, the high costs for delignification and enzymatic hydrolysis currently deter commercialization of softwood bioconversion processes. This study evaluates the abilities of two novel fungal preparations (MSUBC1 and MSUBC2) and two commercial cellulase preparations (TR1 and TR2) to hydrolyze cellulose in Douglas-fir pretreated by steam explosion or ethanol organosolv process. MSUBC1 showed significantly better performance than the other preparations on both lignocellulosic substrates. In particular, MSUBC1 achieved >76% cellulose conversion for hydrolysis of steam-exploded Douglas-fir (～44% lignin) after 72 h at low enzyme loading (10 filter paper units/g of cellulose) and without β-glucosidase supplementation.     

On the photosensitivity of dibenzoylmethane,benzoylacetone and ethyl benzoylacetate in solution

The influence of sunlight on the keto-enol ratio of dibenzoylmethane, benzoylacetone and ethyl benzoylacetate in heptane solution was examined. It was shown that the tautomeric equilibrium is strongly displaced to the keto form. Important differences in the photosensitivity of β-diketones and β-ketoesters depending on the structural features and the nature of irradiation have been established.     

Valuation of the Extraocular Effective Elastance on the Base of Dynamical Model

This paper makes an attempt to answer the question for the effective (functional) value of extraocular elastance. Here, this question is connected with the problem of rhythmicity mechanism of nystagmus phenomena. A likely dynamical model of the nystagmus horizontal motion is proposed by application of the energy and moment of momentum conservation laws to the extraocular muscle. The model is investigated qualitatively and numerically on the base of existing experimental data in the literature. On the base of analysis of obtained results a hypothesis is formulated that the nystagmus horizontal motions present self-oscillations of the considered system.     

Study of Preferential Solvation in Binary Mixtures by Means of Frequency-Domain Fluorescence Spectroscopy

The preferential solvation of 8-N,N-(dimethylamino)-11H-indeno[2,1-a]pyrene, Py(S)DMA, in its transient charge transfer (CT) state in binary solvents such as toluene/DMSO liquid mixtures was studied by means of frequency-domain fluorometry. The data obtained were considered within the following kinetic scheme: the preferential solvation was described by the system of consecutive reversible reactions of which each step is associated with the absorption of one DMSO molecule in the first solvation shell of the fluoresent Py(S)DMA dipolar CT molecule. The rate constants of the first two reversible elementary processes (i.e., the decay of solvation complexes of Py(S)DMA with one and two polar molecules, k _–1 = 1.1 10⁹ s^–1 and k _–2 = 1.4 10⁹ s^–1) were determined.