Neuroprotective Properties of Quinone Reductase 2 Inhibitor M-11, a 2-Mercaptobenzimidazole Derivative

The ability of NQO2 to increase the production of free radicals under enhanced generation of quinone derivatives of catecholamines is considered to be a component of neurodegenerative disease pathogenesis. The present study aimed to investigate the neuroprotective mechanisms of original NQO2 inhibitor M-11 (2-[2-(3-oxomorpholin-4-il)-ethylthio]-5-ethoxybenzimidazole hydrochloride) in a cellular damage model using NQO2 endogenous substrate adrenochrome (125 µM) and co-substrate BNAH (100 µM). The effects of M-11 (10–100 µM) on the reactive oxygen species (ROS) generation, apoptosis and lesion of nuclear DNA were evaluated using flow cytometry and single-cell gel electrophoresis assay (comet assay). Results were compared with S29434, the reference inhibitor of NQO2. It was found that treatment of HT-22 cells with M-11 results in a decline of ROS production triggered by incubation of cells with NQO2 substrate and co-substrate. Pre-incubation of HT-22 cells with compounds M-11 or S29434 results in a decrease of DNA damage and late apoptotic cell percentage reduction. The obtained results provide a rationale for further development of the M-11 compound as a potential neuroprotective agent.     

Tandem Ring-Opening/Double Ring-Closing Synthesis of 1,2,4-Triazolo[1,5-a]pyridines from Chromone-Containing Acrylonitriles

We studied a reaction of chromone-containing acrylonitriles and cyanoacrylates with acid hydrazides. This reaction turned out to be a method for the synthesis of salicyloyl-substituted 1,2,4-triazolo[1,5-a]pyridines. The synthesis developed is a tandem ring-opening/double ring-closing process. This synthetic approach is characterized by low toxic solvents (ethanol, butanol) and mediator (Et₃N), 37–84% yields, non-chromatographic isolation of products, and substrate tolerance (59 examples).     

Predicting phase behavior in aqueous systems without fitting binary parameters I: CP‐PC‐SAFT EOS,aromatic compounds

This study examines an accuracy of CP‐PC‐SAFT attached by the 4C cross‐association scheme and zero values of binary parameters in predicting the high temperature‐high pressure phase behavior in aqueous systems of aromatic compounds containing one and two benzoic rings, CO₂ and cis‐decalin. In spite of the noteworthy complexity of these systems and the entirely predictive nature of the current approach, it correctly predicts the topology of phase behavior and typically yields the quantitatively accurate estimations of critical loci and the hydrocarbon–rich liquid phases in wide range of conditions. The available single phase volumetric data are also predicted accurately. Unfortunately, it is not a case of the water–rich phases exhibiting very small hydrocarbon concentrations. Nevertheless, the model is still capable of capturing the solubility minima characteristic for these phases around the room temperature. Predictions of the recent version of Simplified PC‐SAFT proposed by Liang et al. (2014) are also discussed. © 2017 American Institute of Chemical Engineers AIChE J, 63: 4124–4135, 2017     

Distribution of Salmonella typhimurium in romaine lettuce leaves

Leafy greens are occasionally involved in outbreaks of enteric pathogens. In order to control the plant contamination it is necessary to understand the factors that influence enteric pathogen-plant interactions. Attachment of Salmonella enterica serovar typhimurium to lettuce leaves has been demonstrated before; however, only limited information is available regarding the localization and distribution of immigrant Salmonella on the leaf surface. To extend our knowledge regarding initial pathogen-leaf interactions, the distribution of green-fluorescent protein-labeled Salmonella typhimurium on artificially contaminated romaine lettuce leaves was analyzed. We demonstrate that attachment of Salmonella to different leaf regions is highly variable; yet a higher attachment level was observed on leaf regions localized close to the petiole (7.7 log CFU g⁻¹) compared to surfaces at the far-end region of the leaf blade (6.2 log CFU g⁻¹). Attachment to surfaces located at a central leaf region demonstrated intermediate attachment level (7.0 log CFU g⁻¹). Salmonella displayed higher affinity toward the abaxial side compared to the adaxial side of the same leaf region. Rarely, Salmonella cells were also visualized underneath stomata within the parenchymal tissue, supporting the notion that this pathogen can also internalize romaine lettuce leaves. Comparison of attachment to leaves of different ages showed that Salmonella displayed higher affinity to older compared to younger leaves (1.5 log). Scanning electron microscopy revealed a more complex topography on the surface of older leaves, as well as on the abaxial side of the examined leaf tissue supporting the notion that a higher attachment level might be correlated with a more composite leaf landscape. Our findings indicate that initial attachment of Salmonella to romaine lettuce leaf depends on multiple plant factors pertaining to the specific localization on the leaf tissue and to the developmental stage of the leaf.     

A High Omega-3 Fatty Acid Diet has Different Effects on Early and Late Stage Myeloid Progenitors

The effects of the polyunsaturated omega-3 (n-3) and omega-6 (n-6) fatty acids (FA) on hematopoiesis are complex in that both FA forms are processed into leukotrienes, eicosanoids, and prostaglandins, which can have independent effects. These FA have antagonistic effects in that n-6 FA prostaglandins tend to be pro-proliferative and pro-inflammatory, while the effects of n-3 FA prostaglandins are the opposite. We have previously shown that diets high in n-3 FA reduce the size of the middle to later stage myeloid progenitor compartment in FVB X sv129 F₁hybrid mice. To assay the effects of high n-3 FA diets on earlier stages of myelopoiesis, we fed C57BL/6J mice diets high in n-3 FA or levels of n-3/n-6 FA similar to western diets and assayed the effects on myelopoiesis with flow cytometry and colony forming cell assays. Results indicate an expansion of the common myeloid progenitor cell compartment in high n-3 FA diets, which does not persist into later stages where the number of progenitor cells is actually lower in high n-3 FA fed animals. Investigations in vitro with the hematopoietic stem cell line EML-clone 1 indicate that cells cultured with eicosapentaenoic acid (n-3 FA) or arachidonic acid (n-6 FA) have no differences in cell viability but that arachidonic acid more rapidly produces progenitors with low levels of the macrophage developmental marker, F4/80.     

Real-Time Imaging Using a High-Power Monochromatic Terahertz Source: Comparative Description of Imaging Techniques with Examples of Application

Gradually appearing high-power terahertz sources require the development of adequate imaging techniques. This paper describes four imaging techniques (with a thermal recorder, temperature-sensitive phosphor plates, a visible-light thermal sensitive Fizeau interferometer, and an uncooled microbolometer array) applied with the Novosibirsk terahertz free electron laser as a radiation source. The space and time resolutions of the devices were examined thoroughly. Examples of the application of these techniques, including in-line holography and real-time moving-objects detection, are given.     

Shear-Driven Flow of Locally Heated Viscous Liquid Film in a Minichannel

This paper considers a flow of a liquid sheared by gas in a flat mini-channel with two identical heaters arranged in a row one after another in a streamwise direction at the bottom wall. The present study is focused on the investigation of influence of local heaters arrangement and size on thermocapillary deformations in a viscous film, gravity effect is also investigated. 3D one-sided model is considered, viscosity of the liquid is supposed to be temperature dependent. Numerical analysis reveals that interaction and mutual influence of 3D structures takes place. Film pattern changes qualitatively depending on the heaters arrangement and form. For rectangular heaters a middle stream exists. Minimum film thickness value increases and its location moves to heater edges for rectangular heaters. A critical backlash between two heaters, at which film thinning is the largest, exists. Gravity significantly affects on the film deformations. Decreasing of gravity level leads to a flow destabilization and film deformations, especially film thinning, essentially increases.     

Tailoring Cellular Uptake of Gold Nanoparticles Via the Hydrophilic‐to‐Hydrophobic Ratio of their (Co)polymer Coating

It is demonstrated how cellular uptake and protein corona of (co)polymer‐coated gold nanoparticles can be altered by the hydrophilic‐to‐hydrophobic comonomer ratio. A novel, label‐free flow cytometry strategy is developed to investigate particle uptake. These findings offer insight in the design and analysis of hybrid nanomaterials for interfacing with biological systems.     

Strain mapping of a triple junction in nanocrystalline Pd

Aberration-corrected transmission electron microscopy was used to provide structural information on a triple junction in nanocrystalline Pd. This triple junction consists of two intersecting Σ3 twin boundaries with a Σ9 grain boundary and is connected to a quadruple point via the Σ9 grain boundary. A comprehensive strain analysis of this triple junction using geometric phase analysis is presented and compared with a molecular dynamics simulation. The main results are: (i) the strain field of the core of the triple junction shows dislocation character and extends over a distance of about 0.5 nm; (ii) the intersecting boundaries result in a net translation of , which corresponds to a Burgers vector of an dislocation in the fcc lattice; (iii) a disclination emerging from the triple junction along the Σ9 grain boundary is balanced by a disclination of opposite sign emerging from the quadruple point. Based on the observation that the core of the triple junction can be described by the strain field of a dislocation, its energy was estimated using to be about 1.7 × 10⁻⁹ J m⁻¹. The presence of a disclination dipole is thought to be essential for stabilization of the structure observed.