Environment

After 1812 and the end of the war with Napoleon, Moscow was rebuilt. The great fire of that year accelerated the changes and a new national enthusiasm was reflected in town planning and architecture. The author captures this spirit and introduces to western readers some of the archives of the state, previously unknown.     

Features of structure formation and electrophysical properties of poly(vinylidene fluoride) crystalline ferroelectric polymers

The influence of intramolecular dipole–dipole interaction changes on structure formation peculiarities and some electrophysical properties were investigated with example of copolymers of vinylidene fluoride with tetrafluoroethylene and hexafluoropropylene with different compositions. The decrease of such dipole–dipole interactions in vinylidene fluoride/tetrafluoroethylene copolymers leads to an increase of the a and b parameters of the ferroelectric phase lattice and were accompanied by a shift of the Curie point to lower temperatures. The presence of peak‐halo at angles near 2θ = 18° were attributed to a paraelectric phase localized in the interfacial domains at the crystal–amorphous phase boundaries. Similar peak‐halos for vinylidene fluoride/hexafluoropropylene copolymers crystallizing into the nonpolar α phase were associated with the presence of an antiferroelectric phase formed by the chains in the planar zigzag conformation. The temperature range where dielectric anomalies were detected was characterized by conformational changes at which the decrease in planar zigzag conformation isomers took place. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

One year environmental surveillance of rotavirus specie A (RVA) genotypes in circulation after the introduction of the Rotarix® vaccine in Rio de Janeiro, Brazil

Rotavirus specie A (RVA) infection is the leading cause of severe acute diarrhea among young children worldwide. To reduce this major RVA health impact, the Rotarix^® vaccine (GlaxoSmithKline, Rixensart, Belgium) was introduced in the Brazilian Expanded Immunization Program in March 2006 and became available to the entire birth cohort. The aim of this study was to evaluate the spread of RVA in the environment after the introduction of Rotarix^® in Brazil. For this purpose, a Wastewater Treatment Plant (WTP) in Rio de Janeiro was monitored for one year to detect, characterize and discriminate RVA genotypes and identify possible circulation of vaccine strains. Using TaqMan^® quantitative PCR (qPCR), RVA was detected in 100% (mean viral loads from 2.40 × 10⁵ to 1.16 × 10⁷ genome copies (GC)/L) of sewage influent samples and 71% (mean viral loads from 1.35 × 10³ to 1.64 × 10⁵ GC/L) of sewage effluent samples. The most prevalent RVA genotypes were P[4], P[6] and G2, based on VP4 and VP7 classification. Direct nucleotide sequencing (NSP4 fragment) and restriction enzyme digestion (NSP3) analysis did not detect RVA vaccine-like strains from the sewage samples. These data on RVA detection, quantification and molecular characterization highlight the importance of environmental monitoring as a tool to study RVA epidemiology in the surrounding human population and may be useful on ongoing vaccine monitoring programs, since sewage may be a good screening option for a rapid and economical overview of the circulating genotypes.     

Mechanism and kinetic study for the degradation of lindane by photo-Fenton process

Because application of classical treatment methods cannot allow an easily Lindane (gamma 1α,2α,3β,4α,5α,6β-hexachlorocyclohexane) degradation, development of more powerful water treatment techniques, like advanced oxidation processes (AOPs), was necessary. The degradation of lindane (γ-HCH) has been studied using the photo-Fenton reaction. The degradation kinetics under irradiation was optimized in respect to H₂O₂ concentration and Fe²⁺ concentration at a constant lindane concentration. The degradation rate follows pseudo-first order kinetics with respect to lindane and organic clorine mineralization. Application of photo-Fenton system also assures total organic carbon removal with 95% efficiency at 2 h irradiation. The possible pathways of lindane photodegradation is also proposed.     

Marangoni-induced deformation of evaporating liquid films on composite substrates

Marangoni convection plays an important role in hydrodynamics of evaporating liquid films and sessile drops. Evaporation of liquid films induces unsteady nonuniform temperature distribution across the liquid layer and in a substrate. If the substrate is composed of parts with different thermal properties, the interface temperature distribution becomes non-uniform, leading to appearance of Marangoni stresses, convective vortices, and film deformation. In this article, a model describing evaporation, Marangoni effect and interface dynamics of liquid films on composite substrates is developed. The film dynamics is described in the framework of long-wave theory. The unsteady heat conduction in the substrate is described using the Laplace transform method for semi-infinite substrates and using the separation of variables technique for substrates of finite thickness. The non-uniformity of substrate thermal properties has a pronounced effect on film dynamics.     

Fingering instability of partially wetting evaporating liquids

A numerical study of the fingering instability of the leading edge of a film of evaporating partially wetting liquid flowing down an inclined solid substrate is presented. The effects of capillarity, gravity, disjoining pressure, and evaporation are included in the formulation of our lubrication-type model. The disjoining pressure is assumed to be a linear combination of two components to account for both van der Waals forces and electrostatic effects. Consistent with previously published results, evaporation has a stabilizing effect on fingering instability and can completely suppress the instability if the evaporation number, a nondimensional measure of evaporation intensity, is above a critical value. The critical evaporation number decreases as the inclination angle is decreased. Increasing the apparent contact angle by suitable changes in the disjoining pressure parameters, has a destabilizing influence on the contact line. Also investigated is the length of the fingers in the regime when the instability develops, and it is found that this length decreases as the evaporation number is increased.     

Differential Proteomic Analysis of Astrocytes and Astrocytes-Derived Extracellular Vesicles from Control and Rai Knockout Mice: Insights into the Mechanisms of Neuroprotection

Reactive astrocytes are a hallmark of neurodegenerative disease including multiple sclerosis. It is widely accepted that astrocytes may adopt alternative phenotypes depending on a combination of environmental cues and intrinsic features in a highly plastic and heterogeneous manner. However, we still lack a full understanding of signals and associated signaling pathways driving astrocyte reaction and of the mechanisms by which they drive disease. We have previously shown in the experimental autoimmune encephalomyelitis mouse model that deficiency of the molecular adaptor Rai reduces disease severity and demyelination. Moreover, using primary mouse astrocytes, we showed that Rai contributes to the generation of a pro-inflammatory central nervous system (CNS) microenvironment through the production of nitric oxide and IL-6 and by impairing CD39 activity in response to soluble factors released by encephalitogenic T cells. Here, we investigated the impact of Rai expression on astrocyte function both under basal conditions and in response to IL-17 treatment using a proteomic approach. We found that astrocytes and astrocyte-derived extracellular vesicles contain a set of proteins, to which Rai contributes, that are involved in the regulation of oligodendrocyte differentiation and myelination, nitrogen metabolism, and oxidative stress. The HIF-1α pathway and cellular energetic metabolism were the most statistically relevant molecular pathways and were related to ENOA and HSP70 dysregulation.     

Role of Methylation in Period2 (PER2) Transcription in the Context of the Presence or Absence of Light Signals: Natural and Chemical—Studies on the Pig Model

It has been proposed that carbon monoxide (CO) is a chemical light carrier that is transferred by the humoral pathway from the retina to the brain. Here, we aimed to study how deeply CO is involved in regulating the expression of Period2 gene (PER2), one of the genes maintaining the intrinsic biological clock. In our in vivo experiment, we studied whether CO may be a chemical signal and is also equivalent to natural light in three groups of pigs: Normal: housed in natural conditions without any procedures, Control: adapted and kept in constant darkness, infused with blank plasma, and CO treated: adapted and kept in constant darkness infused with CO-enriched plasma. After the experiment, the animals were slaughtered at two times of day: 12 p.m. and 12 a.m. Next, hypothalamus samples were collected. Quantitative PCR, the DNA methylation of the promoter sequence containing enhancers (E-box) and a functional analysis of the PER2 promoter was performed. qPCR showed a differential pattern of PER2 mRNA expression at daytime oscillation in the examined groups. Pyrosequencing revealed daytime changes in the methylation level of regulatory sites of the examined sequence. Luciferase reporter assay confirmed that E-boxes (CANNTG) drive the expression of the porcine PER2 in vitro. In conclusion, changes in methylation over 24 h may regulate the oscillatory manner of PER2 expression.