Pin1 Regulates IL-5 Induced Eosinophil Polarization and Migration

Eosinophils become polarized in response to cytokines such IL-5 or eotaxin prior to directional migration. Polarization is preceded by F-actin assembly, but the mechanisms that regulate these events and how the shape change influences cell migration from the peripheral blood into the lung remain unclear. In this study, we show that the prolyl isomerase, Pin1, is required for IL-5-induced Eos polarization and migration. Co-immunoprecipitation and immunofluorescence analysis revealed that Pin1 directly interacts with members of Rho GTPase family. Mouse eosinophils lacking Pin1 or human cells treated with Pin1 inhibitors showed significantly reduced IL-5-induced GTPase activity and cofilin phosphorylation, resulting in reduced F-actin polymerization, cell polarization, and directional migration to chemokines. Our result suggests that Pin1 regulates cytoskeletal re-organization, eosinophil morphology, and cell migration through the modulation of Rho GTPase activity. Targeting Pin1 along with GTPases could provide a new approach to reduce pulmonary Eos accumulation during asthmatic exacerbations.

Adsorption and dielectric properties of natural composite polymer wood

The state of water in a natural polymer, wood, was studied by its eff ect on the dielectric parameters and currents of thermostimulated depolarization (TSD) of the adsorption system. It has been shown that surface wood hydroxyls do not play a signifi cant role in the adsorption of water, which occurs mainly in pores of varying volume. Interpretation of the behavior of the TSD currents showed that at the initial stage the polarization linearly depends on the water adsorption value, then this linearity is violated, which we associate with the onset of migration polarization.

Influence of modifying coatings on dielectric permittivity of ceramic materials with composite coatings

The results of research of features of modification of aluminosilicate ceramics by suspension of fluoroplastic, aluminophosphate binder (AFS), non-aqueous compositions of polyurethane components, are presented. Samples of aluminosilicate ceramics for research were obtained by technological methods, including batch preparation operations, sample pressing, pre-annealing and sintering at a temperature of 1200–1350 °C. Polydisperse powders of aluminosilicates obtained by grinding waste of porcelain production (porcelain ware, GOST 28390-89); low-melting clay raw materials were selected as initial components. Modification of surface of aluminosilicate materials was carried out by impregnation of aqueous compositions based on a suspension of fluoroplastic and aluminophosphate binder (AFS), non-aqueous compositions of polyurethane components used in the preparation of polyurethane foam and 5 % solution of polyethylene hydrosiloxane in toluene with the formation of composite coatings on the surface of ceramic materials. It is shown that the application of organic film coatings (based on polyurethane, aluminophosphate binder and a suspension of fluoroplastic-4D, polyethylene hydrosiloxane) leads to formation of a multilayer dielectric material in which there are interface surfaces separating areas with different dielectric properties. In the presence of an external electric field, conditions are created for migration polarization between the crystalline phase of the substrate and the amorphous phase of the coating, due to the redistribution of free charges in the volume of the composite. Moreover, the chemical interaction of AFS with ceramics leads to the smoothing of the surface relief of the aluminosilicate base and the overgrowth of deep pores. Composite “aluminosilicate – AFS-fluoroplastic coating” differs from other materials, primarily in that aluminophosphate binder coating chemically reacts with the ceramic base. The impurity ions introduced during coating application, its composite structure, as well as the heterogeneity of the interface determine the pronounced frequency dependence ε and tgδ, as well as large dielectric losses of the composite in comparison with the original aluminosilicate material.

Электрофизические характеристики многослойных мемристивных наноструктур на основе стабилизированного иттрием диоксида циркония и оксида тантала

The electrophysical characteristics of multilayer memristive structure Au/Ta/ZrO2(Y)/TaOx/TiN have been studied. The effects of electron and ion electrification associated with carrier trapping on traps and ion migration polarization in a dielectric are found. The effect of traps located in dielectrics on the effects of electroforming and resistive switching is established. The values of activation energy and concentrations for traps and ions are determined. The phenomenon of stabilization of resistive switching, which is associated with the features of the two-layer structure of YSZ/TaOx and self-assembled Ta nanoclusters, is found. Nanoclusters play the role of electric field concentrators in the process of electroforming and subsequent resistive switching.

Migracje z państw objętych konfliktami zbrojnymi - analiza wypowiedzi parlamentarzystów na Twitterze

This article aims to analyze the statements published by Polish MPs about the situation of migrants in a social media platform, Twitter. The results of the study show that politicians rarely raise the subject of migration, although a number of important events took place in the international arena regarding the problems of migrants from war-torn areas. Parliamentarians’ tweets are characterized by brevity and generality. They focus on informing about the risks associated with accepting migrants from war-torn areas. A large number of tweets is an appeal for humanitarian aid for migrants. Some posts refer to the chances of development of the Polish economy as a result of economic migration. Parliamentarians’ statements correlate with political, social and psychological factors that are influenced by the complexity of the subject of migration, polarization of public opinion and the existence of stereotypes and prejudice against migrants.

Polarization and sprouting of endothelial cells by angiopoietin-1 require PAK2 and paxillin-dependent Cdc42 activation

Binding of angiopoietin-1 (Ang-1) to its receptor Tie2 on endothelial cells (ECs) promotes vessel barrier integrity and angiogenesis. Here, we identify PAK2 and paxillin as critical targets of Ang-1 responsible for EC migration, polarization, and sprouting. We found that Ang-1 increases PAK2-dependent paxillin phosphorylation and remodeling of focal adhesions and that PAK2 and paxillin are required for EC polarization, migration, and angiogenic sprouting in response to Ang-1. Our findings show that Ang-1 triggers Cdc42 activation at the leading edges of migrating ECs, which is dependent on PAK2 and paxillin expression. We also established that the polarity protein Par3 interacts with Cdc42 in response to Ang-1 in a PAK2- and paxillin-dependent manner. Par3 is recruited at the leading edges of migrating cells and in focal adhesion, where it forms a signaling complex with PAK2 and paxillin in response to Ang-1. These results show that Ang-1 triggers EC polarization and angiogenic sprouting through PAK2-dependent paxillin activation and remodeling of focal adhesions, which are necessary for local activation of Cdc42 and the associated polarity complex. We have shown that PAK2 controls a signaling pathway important for angiogenic sprouting that links focal adhesions to polarity signaling in ECs.

Магнитоэлектрический эффект в парамагнитной области в Gd-=SUB=-0.15-=/SUB=-Mn-=SUB=-0.85-=/SUB=-Sе

In the region of the percolation concentration in the GdxMn1-xSe solid solution, the electric polarization without a field and in 12 kOe magnetic field in the temperature range of 80–380 K was measured . For the composition with x = 0.15, the polarization hysteresis and the dependence of the residual polarization on the magnetic field and temperature were found. The hysteresis is explained in the model of migration polarization and the magnetoelectric effect in the Maxwell-Wagner model.

Механизмы токопереноса и резистивного переключения в конденсаторах со слоями стабилизированного иттрием диоксида гафния

The peculiarities of resistive switching in capacitors with yttria-stabilized hafnia layers were studied. The characteristics of current transport in the initial state and after electroforming and resistive switching at different temperatures were examined. The parameters of a small-signal equivalent circuit of a capacitor were determined for switching into low- and high-resistance states. These parameters suggest that the resistance of filaments changes after each successive switching. This provides an opportunity to use such measurements to determine the nature of resistive switching and verify the reproducibility of its parameters. The contribution of electron traps to switching was revealed. Ion migration polarization was observed at temperatures above 500 K, and the activation energy of ion migration and the ion concentration were determined. The effect of resistive switching under the influence of temperature was observed and interpreted for the first time.