Effect of turbulence on vaporization, mixing, and combustion of liquid-fuel sprays

The effect of turbulence properties on spray flame characteristics has been investigated experimentally in detail. A fine scale fluctuation was imposed on a spray by setting a grid in front of the spray nozzle. This simple way of changing the turbulence characteristics was proved to be a very effective way of increasing evaporation rate of the spray. It was found that the faster evaporation does not necessarily lead to faster combustion. As the turbulence characteristics change, evaporated fuel does not burn instantly but the flame whose characteristics are similar to those of a gaseous diffusion flame rather than to those of a heterogeneous spray flame can be observed. The results indicate that with the increase of evaporation rate, mixing of gaseous fuel and air becomes a controlling process of combustion. In the case of a jet mixing with the ambient air, the mixing between heterogeneous phases is more efficient than that between two homogeneous species. This fact is well known from the study of particle-laden jets. In this study its effects in reacting heterogeneous flows are shown.     

Antimicrobial carbon materials incorporating copper nano‐crystallites and their PLA composites

In the first stage, carbon materials were manufactured from chitin and chitosan as the main precursor. Chitin and chitosan were impregnated with Cu²⁺ ions. Using heat treatment, the organic matter (biopolymers) was transformed into a porous carbon matrix, while copper ions were transformed into copper‐based nano‐crystallites containing copper atoms in a +1 and 0 oxidation state. Such synthesized carbons exhibited high contact antifungal activity, e.g., for sample, CH‐ACu0.1_Ox against R. nigricans the inhibition zone is 10.27 mm. In the second stage, composite polymer films were manufactured by mixing polylactide (PLA) and the obtained microbial carbon material (up to 3 wt % Cu‐carbon content). Despite the very low content of carbon material (3 wt %), the composite PLA films exhibited excellent microbial properties for selected bacteria and fungi, e.g., sample CuCM3%/PLA demonstrated high log₁₀ reduction values of 2.17 and 2.66 for the strains of E. coli and S. aureus, respectively. The composite films, and their components, were examined by means of diversified physicochemical methods like low temperature adsorption of nitrogen, SEM, elemental analysis, XRD, cyclic voltammetry, antifungal, and antibacterial analysis. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43429.     

ADRC in output and error form: connection, equivalence, performance

In this work, we investigate two specific linear ADRC structures, namely output- and error-based. The former is considered a “standard” version of ADRC, a title obtained primarily thanks to its simplicity and effectiveness, which have spurred its adoption across multiple industries. The latter is found to be especially appealing to practitioners as its feedback error-driven structure bares similarities to conventional control solutions, like PI and PID. In this paper, we describe newly found connections between the two considered ADRC structures, which allowed us to formally establish conditions for their equivalence. Furthermore, the conducted comprehensive performance comparison between output- and error-based ADRCs has facilitated the identification of specific modules within them, which can now be conveniently used as building blocks, thus aiding the control designers in customizing ADRC-based solutions and making them most suitable for their applications.     

Nanohydroxyapatite as a Biomaterial for Peripheral Nerve Regeneration after Mechanical Damage—In Vitro Study

Hydroxyapatite has been used in medicine for many years as a biomaterial or a cover for other biomaterials in orthopedics and dentistry. This study characterized the physicochemical properties (structure, particle size and morphology, surface properties) of Li⁺- and Li⁺/Eu³⁺-doped nanohydroxyapatite obtained using the wet chemistry method. The potential regenerative properties against neurite damage in cultures of neuron-like cells (SH-SY5Y and PC12 after differentiation) were also studied. The effect of nanohydroxyapatite (nHAp) on the induction of repair processes in cell cultures was assessed in tests of metabolic activity, the level of free oxygen radicals and nitric oxide, and the average length of neurites. The study showed that nanohydroxyapatite influences the increase in mitochondrial activity, which is correlated with the increase in the length of neurites. It has been shown that the doping of nanohydroxyapatite with Eu³⁺ ions enhances the antioxidant properties of the tested nanohydroxyapatite. These basic studies indicate its potential application in the treatment of neurite damage. These studies should be continued in primary neuronal cultures and then with in vivo models.     

A Tryptophan-Deficient Diet Induces Gut Microbiota Dysbiosis and Increases Systemic Inflammation in Aged Mice

The gut microflora is a vital component of the gastrointestinal (GI) system that regulates local and systemic immunity, inflammatory response, the digestive system, and overall health. Older people commonly suffer from inadequate nutrition or poor diets, which could potentially alter the gut microbiota. The essential amino acid (AA) tryptophan (TRP) is a vital diet component that plays a critical role in physiological stress responses, neuropsychiatric health, oxidative systems, inflammatory responses, and GI health. The present study investigates the relationship between varied TRP diets, the gut microbiome, and inflammatory responses in an aged mouse model. We fed aged mice either a TRP-deficient (0.1%), TRP-recommended (0.2%), or high-TRP (1.25%) diet for eight weeks and observed changes in the gut bacterial environment and the inflammatory responses via cytokine analysis (IL-1a, IL-6, IL-17A, and IL-27). The mice on the TRP-deficient diets showed changes in their bacterial abundance of Coriobacteriia class, Acetatifactor genus, Lachnospiraceae family, Enterococcus faecalis species, Clostridium sp genus, and Oscillibacter genus. Further, these mice showed significant increases in IL-6, IL-17A, and IL-1a and decreased IL-27 levels. These data suggest a direct association between dietary TRP content, the gut microbiota microenvironment, and inflammatory responses in aged mice models.     

Inhibition of Carotenoid Biosynthesis by CRISPR/Cas9 Triggers Cell Wall Remodelling in Carrot

Recent data indicate that modifications to carotenoid biosynthesis pathway in plants alter the expression of genes affecting chemical composition of the cell wall. Phytoene synthase (PSY) is a rate limiting factor of carotenoid biosynthesis and it may exhibit species-specific and organ-specific roles determined by the presence of psy paralogous genes, the importance of which often remains unrevealed. Thus, the aim of this work was to elaborate the roles of two psy paralogs in a model system and to reveal biochemical changes in the cell wall of psy knockout mutants. For this purpose, Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR) and CRISPR associated (Cas9) proteins (CRISPR/Cas9) vectors were introduced to carotenoid-rich carrot (Daucus carota) callus cells in order to induce mutations in the psy1 and psy2 genes. Gene sequencing, expression analysis, and carotenoid content analysis revealed that the psy2 gene is critical for carotenoid biosynthesis in this model and its knockout blocks carotenogenesis. The psy2 knockout also decreased the expression of the psy1 paralog. Immunohistochemical staining of the psy2 mutant cells showed altered composition of arabinogalactan proteins, pectins, and extensins in the mutant cell walls. In particular, low-methylesterified pectins were abundantly present in the cell walls of carotenoid-rich callus in contrast to the carotenoid-free psy2 mutant. Transmission electron microscopy revealed altered plastid transition to amyloplasts instead of chromoplasts. The results demonstrate for the first time that the inhibited biosynthesis of carotenoids triggers the cell wall remodelling.