Self-Voluntary Polymerization with Formation of Quaternary Ammonium Groups

The reaction of spontaneous polymerization in the N, N-dialkylaminoethyl methacrylate - alkyl halide system in organic solvent solutions is considered. It is shown that polymerization in the system under study begins only after the formation of quaternary ammonium salt in the reaction medium (at a concentration of about 0.2 mol/L) by the Menshutkin reaction, as a result of quaternization of the unsaturated amine with an alkyl halide. For the explanation of the aggregate of the obtained experimental data, fundamental considerations were formulated, kinetic schemes were developed, and the corresponding mechanism of polymerization processes was proposed.

Archean to Paleoproterozoic seawater halogen ratios recorded by fluid inclusions in chert and hydrothermal quartz

Past changes in the halogen composition of seawater are anticipated based on the differing behavior of chlorine and bromine that are strongly partitioned into seawater, relative to iodine, which is extremely depleted in modern seawater and enriched in marine sediments due to biological uptake. Here we assess the use of chert, a chemical sediment that precipitated throughout the Precambrian, as a proxy for halide ratios in ancient seawater. We determine a set of criteria that can be used to assess the primary nature of halogens and show that ancient seawater Br/Cl and I/Cl ratios can be resolved in chert samples from the 2.5 Ga Dales Gorge Member of the Brockman Banded Iron Formation, Hamersley Group, Western Australia. The values determined of Br/Cl ~2 × 10-3 M and I/Cl ~30 × 10-6 M are comparable to fluid inclusions in hydrothermal quartz from the 3.5 Ga North Pole area, Pilbara Craton, Western Australia, that were the subject of previous reconstructions of ancient ocean salinity and atmospheric isotopic composition. While the similar Br/Cl and I/Cl values indicate no substantial change in the ocean halide system over the interval 2.5–3.5Ga, compared to modern seawater, the ancient ocean was enriched in Br and I relative to Cl. The I/Cl value is intermediate between bulk Earth (assumed chondritic) and the modern seawater ratio, which can be explained by a smaller organic reservoir because this is the major control on marine iodine at the present day. Br/Cl ratios are about 30% higher than both modern seawater and contemporary seafloor hydrothermal systems, perhaps indicating a stronger mantle buffering of seawater halogens during the Archean.

Neutrophils as Sentinel Cells of the Immune System: A Role of the MPO-halide-system in Innate and Adaptive Immunity

: For decades, neutrophils were generally regarded as the cells of innate immunity with proinflammatory and phagocytic properties involved in a dual activity, beneficial (antimicrobial) and detrimental (tissue damage). Importantly, until the discovery of toll-like receptors (TLRs), a role of neutrophils in adaptive immunity was limited to the effector stage of humoral response and phagocytosis of opsonized antigens. Moreover, in common opinion, neutrophils, as well as the entire innate immune system, were not functionally associated with adaptive immunity. At the time we demonstrated protein chlorination by HOCl, the major product of neutrophil MPO-halide system enhances protein immunogenicity. Based on this discovery, we proposed, as the first, a new role for neutrophils as APC-accessory cells involved in the induction stage of adaptive immunity. Thereafter, we developed our theory concerning the role of neutrophils as the cells which link innate and adaptive immunity. We proposed that protein modification by HOCl may act as a neutrophildependent molecular tagging system, by which sentinel dendritic cells can faster recognise pathogen- derived antigens. Contemporaneously, it was demonstrated that taurine, the most abundant free amino acid in neutrophil cytosol and the major scavenger of HOCl, is a part of the oxidantantioxidant network and is responsible for the regulation and termination of acute inflammation. Moreover, it has been described, that taurine chloramine (TauCl), the physiological products of the reaction of HOCl with taurine, show anti-microbial and anti-inflammatory properties. : In this review, the role of HOCl, taurine and TauCl in innate and adaptive immunity will be discussed.

Functional selective FPR1 signaling in favor of an activation of the neutrophil superoxide generating NOX2-complex

Two formyl peptide receptors (FPR1 and FPR2), abundantly expressed by neutrophils, regulate both pro-inflammatory tissue recruitment of neutrophils and resolution of inflammatory reactions. This dual functionality of the FPRs, opens for a possibility to develop receptor selective therapeutics as mechanism for novel anti-inflammatory treatments. In line with this, high throughput screening studies have identified numerous FPR ligands belonging to different structural classes, but a potent FPR1 agonist with defined biased signaling and functional selectivity has not yet been reported. In this study, we used an FPR1 selective small compound agonist (RE) that represents a chemical entity developed from NOX2 activators identified from our earlier screening studies (WO2012127214). This FPR1 agonist potently activates neutrophils to produce reactive oxygen species (ROS, EC50 ~1 nM), whereas it is a weaker chemoattractant than the prototype FPR1 agonist fMLF. At the signaling level, RE has a strong bias towards the PLC-PIP2-Ca2+ pathway and ERK1/2 activation but away from β-arrestin recruitment and the ability to recruit neutrophils chemotactically. In addition, FPR1 when activated by RE could cross-regulate other receptor-mediated neutrophil functions. In comparison to the peptide agonist fMLF, RE is more resistant to oxidization-induced inactivation by the MPO-H2O2-halide system. In summary, this study describes as a novel FPR1 agonist displaying a biased signaling and functional selectivity when activating FPR1 in human blood neutrophils. RE could possibly be a useful tool compound not only for further mechanistic studies of the regulatory role of FPR1 in inflammation in vitro and in vivo, but also for developing FPR1specific drug therapeutics.

Obtaining the Nanostructured Nitride Composition TiN-BN Powder by the Self-Propagating High-Temperature Synthesis from the Azide KBF4-NaN3-Na2TiF6 and "NH4BF4-NaN3-Na2TiF6 Systems

This paper presents the results of a study on the preparation of nanostructured nitride composition TiN-BN in the boron halide - sodium azide - titanium halide system by the azide SHS technology. SHS-Az technology makes it possible to produce powders having the desired properties, only in one step, without blending separately prepared powders of titanium nitride and boron nitride, and to obtain the final product in the form of micro-and nanosized powder nitride compositions TiN-BN by using complex halides of titanium and boron. Thus, the composite powder TiN and BN obtained from the KBF4-NaN3-Na2TiF6» and «NH4BF4-NaN3-Na2TiF6 systems can be classified as a nanostructured powder (nanopowder).