Acetylated polyethyleneimine (Ac-PEI) effectively immobilized Streptomyces albogriseolus S1 and Bacillus cereus 2-13 on glass and metal surfaces, promoting the formation of stable artificial biofilms resistant to hydrodynamic flows. Immobilized cells remained viable, actively proliferated, and formed dense biofilm layers. These results demonstrate the potential of Ac-PEI for creating microbial coatings on metal surfaces to mitigate microbially induced corrosion.
Three N-alkyl-5-fluoropyrazoles were prepared from the corresponding N-alkylpyrazoles (60-64
Explosion welding of large-scale bimetallic plates remains a major unresolved challenge in the nuclear industry, petrochemical engineering, power generation, shipbuilding, and other sectors, mainly owing to the increased formation of melted regions and structural inhomogeneities that reduce joint strength. These issues are associated with cumulative and shock-wave processes occurring in the gap between the plates before collision. As the plate dimensions increase, both the exposure time of the plate surfaces to the high-temperature shock-compressed gas (SCG) formed in the gap and the amount of dispersed metal particles injected into the gap through cumulative effects become more significant, thereby affecting the SCG parameters. In this study, low-inertia thermoresistive sensors (RTDs) with high spatial resolution were used to measure high-intensity heat fluxes generated by the two-phase flow of gas saturated with dispersed metal particles during explosion welding of copper and steel plates under a wide range of conditions, including variations in plate dimensions and welding regimes (with and without cumulative jet formation). The results show that cumulative processes associated with the high-velocity flow of dispersed metal particles in the gap determine the nonuniform distribution of heat flux along the SCG region. Maximum values (up to 5 GW/m2) are reached near the collision point, the flux stabilizes at approximately 0.1 GW/m2 in the central region, and increases to approximately 0.7 GW/m2 at the shock-wave front. Despite the asymmetry of the cumulative particle flow across the gap height, the thermal effect of the SCG on the flyer and base plates was found to be the same. A twofold increase in plate length (from 0.28 to 0.55 m) leads to a fourfold increase in the heat flux in the central part of the SCG region (from 0.04 to 0.16 GW/m2). The novelty of this research lies in the fact that, for the first time, a dual influence of cumulative effects has been identified: the particles cool the SCG, reducing the heat flux compared to the regime without cumulative jet formation, while the additional momentum transfer from the particles to the gas accelerates the shock wave front (from 1.09 to 1.3-1.4 Vc) and prolongs the duration of thermal exposure.
Woodlice, as one of the key groups, contribute to the decomposition of litter in ecosystems. However, the resource use by woodlice, which likely depends on the body size and developmental stage, remains poorly understood. Understanding ontogenetic shifts in the composition of stable isotopes δ13C and δ15N is essential for assessing the position of woodlice in soil food webs. We applied the stable isotope analysis of carbon and nitrogen to four ontogenetic stages of two synanthropic cosmopolitan woodlice species, Cylisticus convexus and Oniscus asellus, along with their potential food resources in a city park in Moscow, Russia. We compared mancas, juveniles, young adults, and adults. In C. convexus, the δ13C values remained constant, while juveniles, young adults and adults were enriched in 15N compared to mancas. In O. asellus, δ13C values remained constant except for the last age (adults), when they were enriched in 13C by about 1.5‰, compared to other ages. Young adults of O. asellus were depleted in 15N compared to other ages. Bayesian mixing models (MixSIAR) indicated leaf litter as the primary dietary resource for both species, with species-specific differences in the contribution of fungi and moss. These results suggest ontogenetic shifts in resource use within woodlice populations. We demonstrate the need to consider the age of woodlice when interpreting isotopic data and assessing their trophic roles in soil ecosystems.
The disaccharide Galβ1-3GlcNAcα was synthesized and immobilized on Amino Sepharose 6 Fast Flow. Using this adsorbent, antibodies to the disaccharide were isolated from pooled donor blood serum and characterized. These antibodies bound to the polysaccharide from Salmonella enterica strain O59, in which the terminal fragment was Galβ1-3GlcNAcα.
