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Abstract: The method of obtaining new integrable coupled equations through enlarging spectral problems of known integrable equations, which was recently proposed by W.X. Ma, can produce nonintegrable systems as well. This phenomenon is demonstrated and explained by the example of the enlarged spectral problem of the Korteweg–de Vries equation. [Copyright &y& Elsevier]

We study one third-order nonlinear evolution equation, recently introduced by Chou and Qu in a problem of plane curve motions, and find its transformation to the modified Korteweg–de Vries equation, its zero-curvature representation with an essential parameter, and its second-order recursion operator. [Copyright &y& Elsevier]

Abstract: We show how the Yao–Zeng system of coupled short-pulse equations is related to the original short-pulse equation and obtain the correct zero-curvature representation of the Yao–Zeng system via this relationship. [Copyright &y& Elsevier]

The new generalized Harry Dym equation, recently introduced by Z. Popowicz in [Phys. Lett. A 317 (2003) 260], is transformed into the Hirota–Satsuma system of coupled KdV equations. [Copyright &y& Elsevier]

Abstract: A method for fast air purification using high concentration aerosol of TiO2 nanoparticles is evaluated in a model chemical catastrophe involving toxic vapors of diisopropyl fluorophosphate (DFP). Mice are used as human model in a closed 100dm3 chamber. Exposure of mice to 37ppm of DFP vapor for 15min resulted in acute poisoning. Spraying TiO2 aerosol in 2min after the start of exposure to DFP vapors resulted in quick removal of DFP vapors from the chamber''s air. Animals did not show signs of poisoning after the decontamination experiment and exposure to TiO2 aerosol alone. Reactive oxygen species (ROS) and antioxidant activity (AOA) of mice blood plasma were measured for animals exposed to sound of aerosol generator, DFP vapors, TiO2 aerosol and DFP vapors+TiO2 aerosol. Reduced ROS and increased AOA were found for mice exposure to sound, DFP and TiO2 aerosol. Exposure to DFP and decontamination with TiO2 nanoparticles resulted in decreased AOA in 48h following the exposure. The results suggest that application of TiO2 aerosol is a powerful method of air purification from toxic hydrolysable compounds with moderate health aftermaths and requires further study and optimization. [Copyright &y& Elsevier]

• Biomass of Miscanthus from Western Siberia was pretreated with dilute HNO 3 and NaOH. • BC was synthesized by Medusomyces gisevii under non-sterile conditions. • BC quality does not depend on pretreatment method of Miscanthus biomass. Bacterial cellulose (BC) was synthesized from biomass of Miscanthus grown in West Siberia. Miscanthus biomass was pretreated at atmospheric pressure with 4 wt.% solutions of HNO 3 and NaOH in one and two stages. The effect of four methods of the pretreatment of the feedstock on BC yield and properties was examined. The resultant pulps were subjected to enzymatic hydrolysis with commercial CelloLux-A and BrewZyme BGX enzymes. Biosynthesis of BC was run under static and non-sterile conditions using Medusomyces gisevii Sa-12. The two-stage pretreatment of Miscanthus biomass gave a 20 % increase in BC production compared to the single-stage pretreatment. The resultant BC exhibited a high crystallinity index (88–93 %) and an extraordinarily high content of allomorph Iα (99–100 %), irrespective of the pretreatment method; therefore, it has been revealed for the first time that the Medusomyces gisevii Sa-12 symbiotic culture is capable of self-standardization against the quality of produced BC. [ABSTRACT FROM AUTHOR]