PolyHIPE: IPNs, hybrids, nanoscale porosity, silica monoliths and ICP-based sensors

Typical polyHIPE (porous polymers from high internal phase emulsions) have a cellular structure with volume fractions from 0.2 to 0.04, cell diameters from 15 to 25 μm and intercellular pore diameters from 0.5 to 10 μm. Unique interpenetrating polymer networks synthesized within the polyHIPE exhibited enhanced mechanical properties and an extended temperature range for damping. Hybrid polyHIPE that combine an inorganic polysilsesquioxane network with an organic polystyrene network exhibited superior high temperature mechanical properties and enhanced thermal stability. A nanoscale porosity in the cell walls, produced through the addition of a porogen to the HIPE, reduced the density and significantly enhanced the specific surface area. Porous silica monoliths with silica volume fractions of as low as 0.02 were produced through the pyrolysis of hybrid polyHIPE. PolyHIPE coated with an intrinsically conducting polymer exhibited reversible and repeatable changes in conductivity on exposure to acetone vapor, demonstrating their potential as sensor materials.     

Feature-based detection of facial landmarks from neutral and expressive facial images

Feature-based method for detecting landmarks from facial images was designed. The method was based on extracting oriented edges and constructing edge maps at two resolution levels. Edge regions with characteristic edge pattern formed landmark candidates. The method ensured invariance to expressions while detecting eyes. Nose and mouth detection was deteriorated by happiness and disgust.     

Analysis of Antidepressant-like Effects and Action Mechanisms of GSB-106, a Small Molecule,Affecting the TrkB Signaling

Induction of BDNF-TrkB signaling is associated with the action mechanisms of conventional and fast-acting antidepressants. GSB-106, developed as a small dimeric dipeptide mimetic of BDNF, was previously shown to produce antidepressant-like effects in the mouse Porsolt test, tail suspension test, Nomura water wheel test, in the chronic social defeat stress model and in the inflammation-induced model of depression. In the present study, we evaluated the effect of chronic per os administration of GSB-106 to Balb/c mice under unpredictable chronic mild stress (UCMS). It was observed for the first time that long term GSB-106 treatment (1 mg/kg, 26 days) during ongoing UCMS procedure ameliorated the depressive-like behaviors in mice as indicated by the Porsolt test. In addition, chronic per os administration of GSB-106 resulted in an increase in BDNF levels, which were found to be decreased in the prefrontal cortex and hippocampus of mice after UCMS. Furthermore, prolonged GSB-106 treatment was accompanied by an increase in the content of pTrkB^706/707 in the prefrontal cortex and by a pronounced increase in the level of pTrkB⁸¹⁶ in both studied brain structures of mice subjected to UCMS procedure. In summary, the present data show that chronic GSB-106 treatment produces an antidepressant-like effect in the unpredictable chronic mild stress model, which is likely to be associated with the regulation of the BDNF-TrkB signaling.     

Sensitive Immunofluorescent Detection of the PRAME Antigen Using a Practical Antibody Conjugation Approach

Bioconjugation of antibodies with various payloads has diverse applications across various fields, including drug delivery and targeted imaging techniques. Fluorescent immunoconjugates provide a promising tool for cancer diagnostics due to their high brightness, specificity, stability and target affinity. Fluorescent antibodies are widely used in flow cytometry for fast and sensitive identification and collection of cells expressing the target surface antigen. Nonetheless, current approaches to fluorescent labeling of antibodies most often use random modification, along with a few rather sophisticated site-specific techniques. The aim of our work was to develop a procedure for fluorescent labeling of immunoglobulin G via periodate oxidation of antibody glycans, followed by oxime ligation with fluorescent oxyamines. Here, we report a novel technique based on an in situ oxime ligation of ethoxyethylidene-protected aminooxy compounds with oxidized antibody glycans. The approach is suitable for easy modification of any immunoglobulin G, while ensuring that antigen-binding domains remain intact, thus revealing various possibilities for fluorescent probe design. The technique was used to label an antibody to PRAME, a cancer-testis protein overexpressed in a number of cancers. A 6H8 monoclonal antibody to the PRAME protein was directly modified with protected-oxyamine derivatives of fluorescein-type dyes (FAM, Alexa488, BDP-FL); the stoichiometry of the resulting conjugates was characterized spectroscopically. The immunofluorescent conjugates obtained were applied to the analysis of bone marrow samples from patients with oncohematological diseases and demonstrated high efficiency in flow cytometry quantification. The approach can be applied for the development of various immunofluorescent probes for detection of diagnostic and prognostic markers, which can be useful in anticancer therapy.     

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.