Spectroscopic Observation and Ultrafast Coherent Vibrational Dynamics of the Aqueous Phenylalanine Radical

The phenylalanine radical (Phe•) has been proposed to mediate biological electron transport (ET) and exhibit long-lived electronic coherences following attosecond photoionization. However, the coupling of ultrafast structural reorganization to the...

SPECTRAL FEATURES AND HYDROGEN BOND STRUCTURE OF AQUEOUS SOLUTIONS OF ETHANOL

The aim of this work is develop an approach that makes it possible to study the spectral properties and structure of intermolecular hydrogen bonds in aqueous solutions of ethanol formed in systems whose existence in a gaseous medium or an isolated state is practically impossible. This approach bases on the combined use of infrared spectroscopy and molecular dynamics (MD) methods. An analysis give the structural reorganization of water molecules depending on the concentration of ethanol alcohol. It has been shown that the method of molecular dynamics with classical force fields makes it possible to explicitly take into account the molecules of the solvent and solute, and, thus, to investigate hydrogen bonds in the system and to interpret with the experimental data obtained by vibrational spectroscopy.

Infection-induced chromatin modifications facilitate translocation of herpes simplex virus capsids to the inner nuclear membrane

Herpes simplex virus capsids are assembled and packaged in the nucleus and move by diffusion through the nucleoplasm to the nuclear envelope for egress. Analyzing their motion provides conclusions not only on capsid transport but also on the properties of the nuclear environment during infection. We utilized live-cell imaging and single-particle tracking to characterize capsid motion relative to the host chromatin. The data indicate that as the chromatin was marginalized toward the nuclear envelope it presented a restrictive barrier to the capsids. However, later in infection this barrier became more permissive and the probability of capsids to enter the chromatin increased. Thus, although chromatin marginalization initially restricted capsid transport to the nuclear envelope, a structural reorganization of the chromatin counteracted that to promote capsid transport later. Analyses of capsid motion revealed that it was subdiffusive, and that the diffusion coefficients were lower in the chromatin than in regions lacking chromatin. In addition, the diffusion coefficient in both regions increased during infection. Throughout the infection, the capsids were never enriched at the nuclear envelope, which suggests that instead of nuclear export the transport through the chromatin is the rate-limiting step for the nuclear egress of capsids. This provides motivation for further studies by validating the importance of intranuclear transport to the life cycle of HSV-1.

Adeno-associated virus type 2 (AAV2) uncoating is a stepwise process and is linked to structural reorganization of the nucleolus

Nucleoli are membrane-less structures located within the nucleus and are known to be involved in many cellular functions, including stress response and cell cycle regulation. Besides, many viruses can employ the nucleolus or nucleolar proteins to promote different steps of their life cycle such as replication, transcription and assembly. While adeno-associated virus type 2 (AAV2) capsids have previously been reported to enter the host cell nucleus and accumulate in the nucleolus, both the role of the nucleolus in AAV2 infection, and the viral uncoating mechanism remain elusive. In all prior studies on AAV uncoating, viral capsids and viral genomes were not directly correlated on the single cell level, at least not in absence of a helper virus. To elucidate the properties of the nucleolus during AAV2 infection and to assess viral uncoating on a single cell level, we combined immunofluorescence analysis for detection of intact AAV2 capsids and capsid proteins with fluorescence in situ hybridization for detection of AAV2 genomes. The results of our experiments provide evidence that uncoating of AAV2 particles occurs in a stepwise process that is completed in the nucleolus and supported by alteration of the nucleolar structure.

MORPHOLOGICAL CHARACTERISTICS OF GUINEA PIGS BRONCHUS ASSOCIATED LYMPHOID TISSUE IN THE DYNAMICS OF EXPERIMENTAL OVALBUMIN-INDUCED ALLERGIC INFLAMMATION

The actual problem of modern medicine is the reaction of Bronchus associated lymphoid tissue in airways chronic allergic diseases, because the full functioning of the respiratory system depends on the state of its local immune system. The aim – to study morphological changes in Bronchus associated lymphoid tissue of guinea pigs in the dynamics of experimental ovalbumin-induced allergic inflammation. Material and Methods. We have studied the lung of 48 guinea pigs, using histological and morphometric methods, under conditions of experimental ovalbumin-induced allergic inflammation. To assess the structural and functional rearrangement of pulmonary lymphoid nodules, their diameter and number were determined. Results. We have shown that sensitization and allergization with ovalbumin leads to a significant structural and functional rearrangement of Bronchus associated lymphoid tissue of guinea pigs in the form of the elevation in their number and diameter. We found more pronounced morphological changes in the late period of development of allergic inflammation in peribronchial lymphoid nodules, confirmed by the maximum magnification factor – 2.6 (p*/**<0.001) of the diameter of peribronchial lymphoid nodules in the 4th experimental group compared to the control. Conclusions. Sensitization and inhalation with ovalbumin leads to structural reorganization of Bronchus associated lymphoid tissue of guinea pigs in the form of the elevation in their number and diameter, had the unidirectional staged character depending on localization of lymphoid nodules and the duration of the experiment and claimed proliferative changes in the cellular adaptive link of local lung immunity of guinea pigs in late period of allergic inflammatory process.

Formation of regional inter-sectoral complexes of recreation and tourism activity as a sign of structural reorganization of the economy

Changes taking place in recent decades in the global economy have led to the formation and development of new highly differentiated inter-branch complexes, rather than separated industries. In the global economy, such reorganization is marked by the formation of new sectors of the economy, one of which is a sector of socio-natural types of economic activity. At the level of regions, new integration formations are developed - regional inter-sectoral recreational complexes (IcRC). The purpose of our study is to substantiate the formation of regional inter-sectoral complexes of recreational and tourist activities (RTA) in the conditions of radical restructuring of the economy of post-industrial civilization. Inter-sectoral complex RTA is a set of different types of activities of the population - economic and non-economic, as well as leisure forms that provide the needs of the population of the region (countries) in recreation services, health improvement, healing and tourism, accompanying social services and recreational and tourist infrastructure. The study presents an author's vision of the composition and structuring of the regional inter-sectoral complex of recreation and tourism activity. The developed model of the inter-sectoral complex RTA covers all varieties of recreational activities with all its forms - tourism, organized recreation, unorganized (amateur) mass recreation, household recreation. The geographical bases for the formation of regional inter-sectoral recreational complexes are serving recreational and tourist resources - destinations that determine the specialization of the region by types of RTA. Depending on the level of development of RTA in the region, the RTA management systems may form. At the local and regional levels, the RTA nodes will be destinations - local and regional concentration of recreational and tourist resources with appropriate infrastructure. On the global (international) level, RTA retains a network form of a territorial organization, whose nodes are world centres and areas of tourism, as well as the main areas of formation of tourist flows.

Transcriptional expression changes during compensatory plasticity in the prothoracic ganglion of the adult cricket Gryllus bimaculatus

Most adult organisms are limited in their capacity to recover from neurological damage. The auditory system of the Mediterranean field cricket, Gryllus bimaculatus, presents a compelling model for investigating neuroplasticity due to its unusual capabilities for structural reorganization into adulthood. Specifically, the dendrites of the central auditory neurons of the prothoracic ganglion sprout in response to the loss of auditory afferents. Deafferented auditory dendrites grow across the midline, a boundary they normally respect, and form functional synapses with the contralateral auditory afferents, restoring tuning-curve specificity. The molecular pathways underlying these changes are entirely unknown. Here, we used a multiple k-mer approach to re-assemble a previously reported prothoracic ganglion transcriptome that included ganglia collected one, three, and seven days after unilateral deafferentation in adult, male animals. We used EdgeR and DESeq2 to perform differential expression analysis and we examined Gene Ontologies to further understand the potential molecular basis of this compensatory anatomical plasticity. Enriched GO terms included those related to protein translation and degradation, enzymatic activity, and Toll signaling. Extracellular space GO terms were also enriched and included the upregulation of several protein yellow family members one day after deafferentation. Investigation of these regulated GO terms help to provide a broader understanding of the types of pathways that might be involved in this compensatory growth and can be used to design hypotheses around identified molecular mechanisms that may be involved in this unique example of adult structural plasticity.

Variations in Microstructural and Physicochemical Properties of Candelilla Wax/Rice Bran Oil–Derived Oleogels Using Sunflower Lecithin and Soya Lecithin

Candelilla wax (CW) is a well-known oleogelator that displays tremendous oil-structuring potential. Lecithin acts as a crystal modifier due to its potential to alter the shape and size of the fat crystals by interacting with the wax molecules. The proposed work is an attempt to understand the impact of differently sourced lecithin, such as sunflower lecithin (SFL) and soya lecithin (SYL), on the various physicochemical properties of CW and rice bran oil (RBO) oleogels. The yellowish-white appearance of all samples and other effects of lecithin on the appearance of oleogels were initially quantified by using CIELab color parameters. The microstructural visualization confirmed grainy and globular fat structures of varied size, density, packing, and brightness. Samples made by using 5 mg of SFL (Sf5) and 1 mg of SYL (Sy1) in 20 g showed bright micrographs consisting of fat structures with better packing that might have been due to the improvised crystallinity in the said samples. The FTIR spectra of the prepared samples displayed no significant differences in the molecular interactions among the samples. Additionally, the slow crystallization kinetics of Sf5 and Sy1 correlated with better crystal packing and fewer crystal defects. The DSC endotherm displayed two peaks for melting corresponding to the melting of different molecular components of CW. However, all the formulations showed a characteristic crystallization peak at ~40 °C. The structural reorganization and crystal growth due to the addition of lecithin affected its mechanical property significantly. The spreadability test among all prepared oleogels showed better spreadable properties for Sf5 and Sy1 oleogel. The inclusion of lecithin in oleogels has demonstrated an enhancement in oleogel properties that allows them to be included in various food products.

The Dynamics of Mycoplasma gallisepticum Nucleoid Structure at the Exponential and Stationary Growth Phases

The structure and dynamics of bacterial nucleoids play important roles in regulating gene expression. Bacteria of class Mollicutes and, in particular, mycoplasmas feature extremely reduced genomes. They lack multiple structural proteins of the nucleoid, as well as regulators of gene expression. We studied the organization of Mycoplasma gallisepticum nucleoids in the stationary and exponential growth phases at the structural and protein levels. The growth phase transition results in the structural reorganization of M. gallisepticum nucleoid. In particular, it undergoes condensation and changes in the protein content. The observed changes corroborate with the previously identified global rearrangement of the transcriptional landscape in this bacterium during the growth phase transition. In addition, we identified that the glycolytic enzyme enolase functions as a nucleoid structural protein in this bacterium. It is capable of non-specific DNA binding and can form fibril-like complexes with DNA.