Salmonella Typhimurium internalization is variable in leafy vegetables and fresh herbs

Despite washing and decontamination, outbreaks linked to consumption of fresh or minimally-processed leafy greens have been increasingly reported in recent years. In order to assure the safety of produce it is necessary to gain knowledge regarding the exact routes of contamination. Leaf internalization through stomata was previously reported as a potential route of contamination, which renders food-borne pathogens protected from washing and disinfection by sanitizers. In the present study we have examined the incidence (percentage of microscopic fields harboring ≥ 1 GFP-tagged bacteria) of Salmonella Typhimurium on the surface and underneath the epidermis in detached leaves of seven vegetables and fresh herbs. The incidence of internalized Salmonella varied considerably among the different plants. The highest incidence was observed in iceberg lettuce (81 ± 16%) and arugula leaves (88 ± 16%), while romaine (16 ± 16%) and red-lettuce (20 ± 15%), showed significantly lower incidence (P < 0.05). Internalization incidence in fresh basil was 46 ± 12%, while parsley and tomato leaves demonstrated only marginal internalization (1.9 ± 3.3% and 0.56 ± 1.36%, respectively). Internalization of Salmonella in iceberg lettuce largely varied (0-100%) through a 2 year survey, with a higher incidence occurring mainly in the summer. These results imply that Salmonella internalization occurs in several leafy vegetables and fresh herbs, other than iceberg lettuce, yet the level of internalization largely varies among plants and within the same crop. Since internalized bacteria may evade disinfection, it is of great interest to identify plants which are more susceptible to bacterial internalization, as well as plant and environmental factors that affect internalization.     

Bulk Microstructure of Modern Composites Studied Jointly by Impulse Acoustic Microscopy and X‐ray Microtomography Techniques

Two key techniques—impulse acoustic microscopy and X‐ray microtomography—have been applied in combination for studying bulk microstructure in polymer composites whose properties critically depend on their spatial organization; nanocomposites and fiber reinforced plastics. It has been shown that the both techniques are able to represent three‐dimensional (3D) internal structure with micron resolution. The technique is based on different principles of 3D imaging and employs distinct mechanisms of contrast for microstructure displaying. In many cases, they are complementary in 3D microstructure recovering. POLYM. ENG. SCI., 59:2508–2513, 2019. © 2019 Society of Plastics Engineers     

Processing Pine Wood into Vanillin and Glucose by Sequential Catalytic Oxidation and Enzymatic Hydrolysis

Extractive-free pine wood was processed into vanillin (up to 18 wt.% of the initial lignin) and cellulose (typically 84–93% of the initial amount in the wood) by one-step catalytic oxidation followed by enzymatic hydrolysis of the resulting cellulose into glucose (reducing sugar yield up to 70% based on the post-oxidation cellulose). Correlation between the cellulose conversion in hydrolysis and the lignin content in the post-oxidation lignocellulosic material was established, which follows the general trend for the products of various delignification methods. The obtained results demonstrate the practical possibility of efficient two-step processing of wood into vanillin and glucose.     

Epoxy composites modified with microfibers of potassium polytitanates

The research we conducted shows the possibility of the directed adjustment of epoxy composite performance characteristics through the application of small additives of potassium polytitanate whiskers, the introduction of polyfunctional plasticizers with chemical and mechanical methods of activation of the whole composition and its components; this ensured the creation of a new generation of epoxy composites with high‐performance properties (breaking tension = 116 MPa and modulus of elasticity at bending = 3150 MPa, destructive tension under compression = 95 MPa, impact strength = 18 kJ/m² that meets the requirements of most industries. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 46651.     

Extractive denitrogenization of liquid model fuel using polyethylene glycol methyl ether 350

In the present study, we studied the effectiveness of the water-soluble polymer polyethylene glycol methyl ether 350 (PEG ME-350) on the extraction of nitrogen-containing heterocyclic compounds—quinoline and indole—from n-hexane. The dependences of the quantitative characteristics of the extraction of N-compounds on the contact time of the phases, the content of PEG ME-350 in the n-hexane–water system, the initial concentration of nitrogen-containing heterocyclic compounds in the organic phase, and the volumetric ratio of the phases were obtained. It has been established that PEG ME-350 is an effective extractant in the process of stepwise extraction of quinoline and indole, and the mechanisms of their extraction have also been proposed and proven. The results can be further used in the purification of light hydrocarbon fractions from nitrogen-containing heterocyclic compounds.     

Determination of the total acid number (TAN) of used gas engine oils by IR and chemometrics applying a combined strategy for variable selection

The most common analyses carried out to assess gas engine oil quality include determination of viscosity, total base number (TBN), and total acid number (TAN). TAN has been considered to be an important indicator of oil quality, specifically in terms of defining oxidation and the extent of acidic contamination of used oils. TAN can be determined by potentiometric titration, and typical values for used oils can reach up to 4 mg KOH/g. A more convenient approach for the determination of TAN is based on infrared (IR) spectral data and multivariate regression models.We developed partial least-squares (PLS) models for the determination of TAN using IR data measured from monograde mineral gas engine oils (SAE 40, medium ash) that have been used in sewer and wood gas engines run with gaseous fuels from a sewage plant and a wood gasification plant, respectively. The final model performance was 0.07 mg KOH/g for the standard error of prediction (SEP). Essential for the development of powerful empirical models was an appropriate variable selection by combining expert knowledge, biPLS or dyn-biPLS, and a genetic algorithm. The optimum complexities of the models (the number of PLS components) and their prediction performances have been estimated by repeated double cross validation (rdCV).     

Experimental Study of the Effect of Metal Nanopowders on the Decomposition of HMX,AP and AN

The effect of metal nanopowders (Al, Fe, W, Ni, Cu, and Cu‐Ni alloys) on the decomposition of energetic materials (HMX, AP, and AN) with DTA–TGA method was studied and it was found that the catalytic action appears in the case of Cu‐Ni nanopowders with the three studied energetic materials. The temperature of decomposition of energetic materials with the addition of metal nanopowders could be lowered by 82 °C for AN, 161 °C for AP, and 96 °C for HMX. The reaction mechanism of metal nanopowders enhancing the decomposition of energetic materials is discussed.     

Self-focused attention and emotional reactivity: The role of culture.

Research conducted with European Americans suggests that attention to the individual self intensifies emotional reactivity. We propose, however, that cultural models of the self determine which aspect of the self (individual vs. relational), when attended to, intensifies emotional reactivity. In 3 studies, we predicted and observed that attention to individual aspects of the self was associated with levels of emotional reactivity that were greater in individuals from European American contexts (which promote an independent model of the self) than in individuals from Asian American contexts (which promote an interdependent model of the self). In contrast, attention to relational aspects of the self was associated with levels of emotional reactivity that were similar or greater in individuals from Asian American than in individuals from European American contexts. These findings highlight the importance of considering cultural and situational factors when examining links between the self and emotion. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Depression and emotional reactivity: Variation among Asian Americans of East Asian descent and European Americans.

Studies of Western samples (e.g., European Americans [EAs]) suggest that depressed individuals tend to show diminished emotional reactivity (J. G. Gehricke & A. J. Fridlund, 2002; G. E. Schwartz, P. L. Fair, P. Salt, M. R. Mandel, & G. L. Klerman, 1976a, 1976b). Do these findings generalize to individuals oriented to other cultures (e.g., East Asian cultures)? The authors compared the emotional reactions (i.e., reports of emotional experience, facial behavior, and physiological reactivity) of depressed and nondepressed EAs and Asian Americans of East Asian descent (AAs) to sad and amusing films. Their results were consistent with previous findings: Depressed EAs showed a pattern of diminished reactivity to the sad film (less crying, less intense reports of sadness) compared with nondepressed participants. In contrast, depressed AAs showed a pattern of heightened emotional reactivity (greater crying) compared with nondepressed participants. Across cultural groups, depressed and nondepressed participants did not differ in their reports of amusement or facial behavior during the amusing film. Physiological reactivity to the film clips did not differ between depressed and control participants for either cultural group. Thus, although depression may influence particular aspects of emotional reactivity across cultures (e.g., crying), the specific direction of this influence may depend on prevailing cultural norms regarding emotional expression. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Spatially resolved non-invasive chemical stimulation for modulation of signalling in reconstructed neuronal networks.

Functional coupling of reconstructed neuronal networks with microelectronic circuits has potential for the development of bioelectronic devices, pharmacological assays and medical engineering. Modulation of the signal processing properties of on-chip reconstructed neuronal networks is an important aspect in such applications. It may be achieved by controlling the biochemical environment, preferably with cellular resolution. In this work, we attempt to design cell-cell and cell-medium interactions in confined geometries with the aim to manipulate non-invasively the activity pattern of an individual neuron in neuronal networks for long-term modulation. Therefore, we have developed a biohybrid system in which neuronal networks are reconstructed on microstructured silicon chips and interfaced to a microfluidic system. A high degree of geometrical control over the network architecture and alignment of the network with the substrate features has been achieved by means of aligned microcontact printing. Localized non-invasive on-chip chemical stimulation of micropatterned rat cortical neurons within a network has been demonstrated with an excitatory neurotransmitter glutamate. Our system will be useful for the investigation of the influence of localized chemical gradients on network formation and long-term modulation.