Redistribution Of Components Research Articles

On Thermocapillary Mechanism of Spatial Separation of Metal Melts

Theoretical research has been devoted to the study of binary metal melts behavior in a thin capillary. Earlier it has been found experimentally that unusually significant and quick redistribution of melts components takes place along capillary after the cooling. Numerical simulation of concentration-induced convection has been carried out to explain these experimental data. Two-component melt of both liquid metals filling vertical thin capillary with non-uniform temperature distribution on the boundaries is considered. It is assumed that the condition of absolute non-wetting is valid on the sidewalls. Because of this effect there is a free surface on vertical boundaries, where thermocapillary force is appeared due to the external longitudinal temperature gradient. It makes to move liquid elements at a big distance, compared with axial size of capillary. Effects of adsorption-desorption on the surface, thermal and concentration-capillary forces, convective motion in a volume and diffusion generate the large-scale circulation. This process includes the admixture carrying-out on the surface in the more hot higher part of the channel, its following transfer down along the boundary due to the thermocapillary force and its return in the volume over the desorption in the lower part of capillary. Intensity of motion and processes of adsorption-desorption on the free boundary have the decisive influence upon the formation of concentration fields and speed of components redistribution. Thus, one of the possible mechanisms of longitudinal division on components of liquid binary mixtures in thin channels has been demonstrated.

Effect of UV-light irradiation on phase diagram of lyotropic chromonic liquid crystal

We demonstrate that the phase diagram of a Lyotropic Chromonic Liquid Crystal (LCLC) is affected by ultraviolet (UV) light irradiation. UV-irradiation induces a phase transition from the nematic (N) to isotropic (I) state at a fixed temperature. Birefringence measured in-situ decreases under irradiation, until the moment when the isotropic phase starts to nucleate and the initial homogeneous nematic transforms into a biphasic state. On further irradiation the birefringence of the N fraction of the biphasic I-N state increases revealing redistribution of the composition components between the two coexisting phases. The efficiency of the irradiation-induced changes depends on the orientation of the chromonic aggregates w.r.t. the polarization of UV light. Changes of the birefringence are noticeably higher for light polarization perpendicular to the nematic director. The effect can be understood as a photo-induced weakening of the face-to-face molecular attraction within the chromonic aggregates and the resulting shortening of these aggregates.

Experimental modeling of the conditions for the Formation of Precambrian weathering profiles. Composition of solutions and redistribution of lanthanides

Experimental test data of paleproterozoic granitoids leaching in oxygen and argon conditions and in various acid alkaline environments showed that active leaching and forming of solutions with total cations concentration of more than 20mg/l and K/Na>1 can only occur in an acid oxiditation environment. In humid conditions solutions with negative cerium anomaly are forming, when in arid conditions the cerium anomaly does not exist. During the formation of hypergene profiles in the Early Precambrian there was a redistribution of components between the residual material of the weathering crust and the authigenic component. The residual part of the weathering crust is combined with LREE while the authigenous component of the weathering crust got enriched with the leached components. Drained solution at the outlet of the hypergene profile has acquired ultrafresh characteristics, but a higher ratio Rb/Sr and K/Na.

Effect of micronisation on dietary fibre content and hydration properties of lotus node powder fractions

SummaryFibre‐rich fractions were obtained from nodes of lotus root and micronised by nine different ball‐milling treatments. The optimum milling conditions were screened out by comparing its effects on physicochemical and hydration properties of micro‐sized particles of lotus node powder fraction (LNPF). The micronisation by ball‐milling treatments was carried out at different speeds (200–400 r min−1) and time (4–12 h). Ball‐milling treatments could effectively (P < 0.05) pulverise the LNPF particles to different micro‐sizes. As particle size decreased, a redistribution of fibre components from insoluble to soluble fractions was observed. Furthermore, micronisation treatments, especially 12 h at 300 r min−1, could significantly (P < 0.05) increase the hydration characteristics, as well as impart lightness in colour to different extents. Our findings suggested that micronisation can improve physicochemical and hydration characteristics of the fibre components, which provide an opportunity to improve the utilisation and application of lotus node dietary fibre.

Availability of four energy crops assessing by the enzymatic hydrolysis and structural features of lignin before and after hydrothermal treatment

The anatomical characteristics, chemical composition, enzymatic hydrolysis efficiency and lignin characteristics of four energy crops (switchgrass, Miscanthus × giganteus, Hybrid Pennisetum, and Triarrhena lutarioriparia) before and after hydrothermal treatment (180 °C, 1 h) were investigated comprehensively to evaluate their potential for the bioenergy production. The hydrothermal treatment resulted in the deconstruction of the biomass cell walls and redistribution of the main components, accompanying with the removal of most hemicelluloses and partial lignin as well as favorable exposure of cellulose. These alterations significantly increased the efficiency of enzymatic hydrolysis, and the different recalcitrance of the four feedstocks was evenly erased by hydrothermal treatment. Among the four crops, Hybrid Pennisetum with high cellulose and low lignin contents had a better performance in the enzymatic hydrolysis process both before and after treatment. Meanwhile, the maximum concentration of low degree of polymerization xylo-oligosaccharides (2-6) and the lowest amount of degraded products were obtained from Hybrid Pennisetum during the treatment process. Moreover, the structural features of the residual lignin in the treated substrates were elaborately analyzed for deeply understanding the fundamental chemistry of lignin during the treatment. The present study is beneficial to the fully effective utilization of biomass components and extension of the energy sources.

Hydrosilicate liquids in the system rare-metal granite–Na2O–SiO2–H2O as accumulators of ore components at high pressure and temperature

Experimental investigations in the system rare-metal granite–Na2O–SiO2–H2O with the addition of aqueous solutions containing Rb, Cs, Sn, W, Mo, and Zn at 600°C and 1.5 kbar showed that the typical elements of rare-metal granites (Li, Rb, Cs, Be, Nb, and Ta) are preferentially concentrated in hydrosilicate liquids coexisting with aqueous fluid. The same behavior is characteristic of Zn and Sn, the minerals of which are usually formed under hydrothermal conditions. In contrast, Mo and W are weakly extracted by hydrosilicate liquids and almost equally distributed between them and aqueous fluids. Liquids similar to those described in this paper are formed during the final stages of magmatic crystallization in granite and granite-pegmatite systems. The formation of hydrosilicate liquids in late magmatic and postmagmatic processes will be an important factor controlling the redistribution of metal components between residual magmatic melts, minerals, and aqueous fluids and, consequently, the mobility of these components in fluid-saturated magmatic systems enriched in rare metals.

Scaling rockburst hazard using the DDA and GSI methods

We examine the influence of rock mass quality, as scaled by the Geological Strength Index (GSI), on energy redistribution in tunnels driven through discontinuous rock masses. We assume that in blocky rock masses rockbursts develop asabrupt motion of finite rigid blocks along pre-existing discontinuities rather than by fracture of intact rock elements. We begin by formulating analytically the local energy density around a tunnel in continuous, homogenous, isotropic, linear-elastic medium and demonstrate the significance of the initial principal stress ratio on the result. We then introduce discontinuities into the rock mass and find analytically the peak acceleration of an ejected keyblock when it flies into the tunnel space, to demonstrate the viability of this mechanism asa potential rockbursting source. Using the numerical discontinuous deformation analysis (DDA) method we find the total kinetic energy released during rockbursting and validate our DDA results using monitored seismic energy emissions detected during an intensive rockburst event encountered while excavating one of the headrace tunnels at Jinping II hydroelectric project in China. Utilizing an analytical solution we published earlier for the redistribution of energy components due to tunneling, we explore the effect of rock mass quality as scaled by GSI on the elastic strain energy, dissipated energy, and kinetic energy. We find that the elastic strain energy and the energy dissipated by shear generally decrease with increasing GSI value. The kinetic energy of rockbursts however shows a more complicated behavior. It is low at low quality rock masses, peaks at GSI value of about 60, and decreases again with increasing rock mass quality. This result is supported by documented rockbursts during excavation of the deep tunnels of the Jinping II hydropower project, where the majority of rockbursts were recorded in tunnel segments with characteristic GSI values between 60 and 75.

UV-Vis and ATR-FTIR spectroscopic investigations of postmortem interval based on the changes in rabbit plasma.

Estimating PMI is of great importance in forensic investigations. Although many methods are used to estimate the PMI, a few investigations focus on the postmortem redistribution. In this study, ultraviolet–visible (UV–Vis) measurement combined with visual inspection indicated a regular diffusion of hemoglobin into plasma after death showing the redistribution of postmortem components in blood. Thereafter, attenuated total reflection–Fourier transform infrared (ATR–FTIR) spectroscopy was used to confirm the variations caused by this phenomenon. First, full-spectrum partial least-squares (PLS) and genetic algorithm combined with PLS (GA-PLS) models were constructed to predict the PMI. The performance of GA-PLS model was better than that of full-spectrum PLS model based on its root mean square error (RMSE) of cross-validation of 3.46 h (R2 = 0.95) and the RMSE of prediction of 3.46 h (R2 = 0.94). The investigation on the similarity of spectra between blood plasma and formed elements also supported the role of redistribution of components in spectral changes in postmortem plasma. These results demonstrated that ATR-FTIR spectroscopy coupled with the advanced mathematical methods could serve as a convenient and reliable tool to study the redistribution of postmortem components and estimate the PMI.

Photodynamic therapy with TMPyP – Porphyrine induces mitotic catastrophe and microtubule disorganization in HeLa and G361 cells, a comprehensive view of the action of the photosensitizer

Photodynamic therapy (PDT) is a useful tool against cancer and various other diseases. PDT is capable to induce different cell death mechanisms, due to the PDT evoked reactive oxygen species (ROS) production and is dose dependent. It is known that cytoskeleton is responsible for numerous cell functions, including cell division, maintenance of cell shape, their adhesion ability and movement. PDT initiated redistribution and subsequent disintegration of cytoskeletal components that precedes cell death. Here was present our results in HeLa and G361 cells subjected to sublethal PDT treatments using α,β,χ,δ porphyrin-Tetrakis (1-methylpyridinium-4-yl) p-Toluenesulfonate porphyrin (TMPyP). The photosensitizer (PS) induced transient increasing of mitotic index (MI) observable early after PDT, cell cycle arrest, microtubule (MTs) disorganization of interphase cells, aberrant mitosis and formation of rounded cells with partial loss of adherence. Some cells were partly resistant to PDT induced MTs disorganization. The differences between both cell lines to PDT response were described. This is the first evidence of TMPyP - PDT induced microtubule disorganization and the cell death mechanisms known as mitotic catastrophe and the first detail analysis of microtubule aberrations of mitotic and interphase cells in HeLa and G361 cell lines. New modification of techniques of protein immunolabeling was developed.

Structure-function relationship of the influenza fusion peptide

Influenza is an enveloped virus which enters the host cell through en-docytosis-mediated mechanism. To enable the release genetic material, a process of fusion between viral and host cell membranes occurs, which is mediated by influenza hemagglutinin (HA) protein. The N-terminal fragment of hemagglutinin HA2 subunit, directly interacting with the membrane, is named a fusion peptide (HAfp), since it is able to promote fusion also as a synthetic fragment. Its C-terminal part contains three residues (W21-Y22-G23), which are highly conserved among various serotypes of Influenza A. It has been shown that the peptide length has an influence on its structure: HAfp1-20 forms a boomerangin contrast to a tight helical hairpin formed by HAfp1-23. To gain more insight into the role of the conserved residues, we studied the effect of peptide length on fusion properties, its structural dynamics, and par-titioning to the phospholipid bilayer. By means of molecular dynamics simulations and spectroscopic measurements, we showed that the presence of three C-terminal residues in HAfp1-23 promotes the for-mation of hairpin structure. In contrast to less structured HAfp1-20,it orients perpendicularly to the membrane plane and induces more disorder in the surrounding lipids. Using a novel fusion visualization assay based on FLIM microscopy on giant unilamellar vesicles (GUV), we observed that HAfp1-23 promotes fusion to a higher extent than HAfp1-20. Moreover, we report cholesterolenriched domain formation exclusively by the longer fusion peptide. This redistribution of membrane components in fluid phases is likely to play a role during membrane fusion.

Non-Canonical Roles of Dengue Virus Non-Structural Proteins.

The Flaviviridae family comprises a number of human pathogens, which, although sharing structural and functional features, cause diseases with very different outcomes. This can be explained by the plurality of functions exerted by the few proteins coded by viral genomes, with some of these functions shared among members of a same family, but others being unique for each virus species. These non-canonical functions probably have evolved independently and may serve as the base to the development of specific therapies for each of those diseases. Here it is discussed what is currently known about the non-canonical roles of dengue virus (DENV) non-structural proteins (NSPs), which may account for some of the effects specifically observed in DENV infection, but not in other members of the Flaviviridae family. This review explores how DENV NSPs contributes to the physiopathology of dengue, evasion from host immunity, metabolic changes, and redistribution of cellular components during infection.

Drosophila Atlastin in motor neurons is required for locomotion and presynaptic function.

Hereditary spastic paraplegias (HSPs) are characterized by spasticity and weakness of the lower limbs, resulting from length-dependent axonopathy of the corticospinal tracts. In humans, the HSP-related atlastin genes ATL1-ATL3 catalyze homotypic membrane fusion of endoplasmic reticulum (ER) tubules. How defects in neuronal Atlastin contribute to axonal degeneration has not been explained satisfactorily. Using Drosophila, we demonstrate that downregulation or overexpression of Atlastin in motor neurons results in decreased crawling speed and contraction frequency in larvae, while adult flies show progressive decline in climbing ability. Broad expression in the nervous system is required to rescue the atlastin-null Drosophila mutant (atl2 ) phenotype. Importantly, both spontaneous release and the reserve pool of synaptic vesicles are affected. Additionally, axonal secretory organelles are abnormally distributed, whereas presynaptic proteins diminish at terminals and accumulate in distal axons, possibly in lysosomes. Our findings suggest that trafficking defects produced by Atlastin dysfunction in motor neurons result in redistribution of presynaptic components and aberrant mobilization of synaptic vesicles, stressing the importance of ER-shaping proteins and the susceptibility of motor neurons to their mutations or depletion.

Actomyosin-dependent dynamic spatial patterns of cytoskeletal components drive mesoscale podosome organization.

Podosomes are cytoskeletal structures crucial for cell protrusion and matrix remodelling in osteoclasts, activated endothelial cells, macrophages and dendritic cells. In these cells, hundreds of podosomes are spatially organized in diversely shaped clusters. Although we and others established individual podosomes as micron-sized mechanosensing protrusive units, the exact scope and spatiotemporal organization of podosome clustering remain elusive. By integrating a newly developed extension of Spatiotemporal Image Correlation Spectroscopy with novel image analysis, we demonstrate that F-actin, vinculin and talin exhibit directional and correlated flow patterns throughout podosome clusters. Pattern formation and magnitude depend on the cluster actomyosin machinery. Indeed, nanoscopy reveals myosin IIA-decorated actin filaments interconnecting multiple proximal podosomes. Extending well-beyond podosome nearest neighbours, the actomyosin-dependent dynamic spatial patterns reveal a previously unappreciated mesoscale connectivity throughout the podosome clusters. This directional transport and continuous redistribution of podosome components provides a mechanistic explanation of how podosome clusters function as coordinated mechanosensory area.

Lateral redistribution of transmembrane proteins and liquid-ordered domains in lipid membranes with inhomogeneous curvature

A number of processes in living cells are accompanied by significant changes of the geometric curvature of lipid membranes. In turn, heterogeneity of the lateral curvature can lead to spatial redistribution of membrane components, most important of which are transmembrane proteins and liquid-ordered lipid-protein domains. These components have a so-called hydrophobic mismatch: the length of the transmembrane domain of the protein, or the thickness of the bilayer of the domain differ from the thickness of the surrounding membrane. In this work we consider redistribution of membrane components with hydrophobic mismatch in membranes with non-uniform geometric curvature. Dependence of the components’ energy on the curvature is calculated in terms of theory of elasticity of liquid crystals adapted to lipid membranes. According to the calculations, transmembrane proteins prefer regions of the membrane with zero curvature. Liquid-ordered domains having a size of a few nm distribute mainly into regions of the membrane with small negative curvature appearing in the cell plasma membrane in the process of endocytosis. The distribution of domains of a large radius is determined by a decrease of their perimeter upon bending; these domains distribute into membrane regions with relatively large curvature.

Roles of composts in soil based on the assessment of humification degree of fulvic acids

This study was conducted to assess the humification degree in fulvic acids (FA) from different composts, and to reveal their roles after soil amending based on their excitation-emission matrices (EEM) of the fluorescence spectra and projection pursuit regression (PPR) analysis. Two peaks were detected in EEM spectra of FA from all composts, and three components were identified by the parallel factor analysis (PARAFAC) model. The assessment of the humification degree of FA using the ratios between the values of the percent fluorescence response in the visible and ultraviolet regions (PI,n/PII,n) generally agreed with that using the distributions of FA components (C1, C2 and C3). The PPR considering the parameters (PI,n/PII,n, C1, C2 and C3) further ranked the composts with similar of FA, and the FA humification degree decreased in the order: GW, TSW, LW and SW>CM, MSW, and PM>MC and KW. The results showed that the compositions of FA were similar to each other in composts from different materials, but there were distinct differences in the humification degree of FA owing to the different distributions of each component in composts. Therefore, based on the redistribution of components, a method for regulating the humification degree of FA during composting was presented. Furthermore, the suitable soil application of composts with different humification degrees was also demonstrated.

Geology and mineralogy of the Alakha spodumene granite porphyry deposit, Gorny Altai, Russia

The Alakha lithium–tantalum deposit in the southern Altai, Russia, is represented by a stock of spodumene-bearing granite porphyry localized in the Kalba–Narym–Koktogai lithium–tantalum rare-metal granitic belt, unique in extent (more than 1000 km). This belt is a part of the Altai accretionary–collisional system. Judging from forecasting, the Alakha deposit can be regarded as an uneroded proxy of a pegmatite body both in dimensions and mean Li2O and Ta2O5 contents (0.98 wt % and 114 ppm, respectively); however, the oregenerating potential of this deposit remains insufficiently studied and had not yet been claimed. In this paper, we attempt to fill this gap with a detailed mineralogical study, which allows us to provide insights into the crystallization of Li-bearing high-silicic magma and redistribution of components during magmatic and postmagmatic processes. Accessory mineral assemblages in muscovite–spodumene–K-feldspar granite porphyry and muscovite albitite—the main petrographic rock varieties of the Alakha stock—turned out to be almost identical. A significant similarity in the chemistry of major rock-forming minerals is established for spodumene granite porphyry of the Alakha stock and spodumene pegmatites from large deposits, which makes it possible to suggest that they are close in the petrogenetic mechanism of their formation. The mineral assemblages of muscovite albitite in the apical portion of the Alakha stock are connected by gradual transition with those of spodumene granite porphyry. Such a transition is caused by postmagmatic metasomatic alteration of the latter.

Features of the Fine Structure of the Active Layers of Organic Solar Cells

The article is devoted to investigation of fine structure of the active layers of organic solar cells. By using atomic forth microscopy (AFM) and transmission electron microscopy (TEM) it is clearly shown that thermal treatment of active layers at 150 °C for 10 minutes leads to increasing their crystallinity. During annealing processes of diffusion redistribution of the film components are activated, and this is accompanied by both the growth of the original crystalline phase and the formation of new crystals.

Acylhydrazone-based dynamic combinatorial libraries: study of the thermodynamic/kinetic evolution, configurational and coordination dynamics

Se describe la selectividad cinética y termodinámica de la formación de acil-hidrazona en librerías combinatorias dinámicas (DCL). Se generaron reacciones competitivas a partir de hidrazidas: isoniazida, 4-nitro-benzohidrazida, 4-dimetilamino-benzohidrazida y hidrazida nicotínica; así como a partir de los derivados de aldehído: benzaldehído y 2-piridin-carboxaldehido. Las especies obtenidas y la distribución de los DCLs fueron monitoreados mediante espectroscopia 1H-NMR, encontrándose que las acil-hidrazonas que contenían la 4-dimetilamino-benzohidrazida son tanto el producto cinético, como el termodinámico de sus respectivas librerías. También se investigaron las dinámicas de configuración y de coordinación para algunas de estas librerías. Los resultados obtenidos permitieron estudiar la redistribución de los componentes y la amplificación de uno o más productos usando luz e iones metálicos como plantillas físicas y químicas, respectivamente.

Subcellular redistribution and sequential recruitment of macromolecular components during SGIV assembly.

Virus infection consists of entry, synthesis of macromolecular components, virus assembly and release. Understanding of the mechanisms underlying each event is necessary for the intervention of virus infection in human healthcare and agriculture. Here we report the visualization of Singapore grouper iridovirus (SGIV) assembly in the medaka haploid embryonic stem (ES) cell line HX1. SGIV is a highly infectious DNA virus that causes a massive loss in marine aquaculture. Ectopic expression of VP88GFP, a fusion between green fluorescent protein and the envelope protein VP088, did not compromise the ES cell properties and susceptibility to SGIV infection. Although VP88GFP disperses evenly in the cytoplasm of non-infected cells, it undergoes aggregation and redistribution in SGIV-infected cells. Real-time visualization revealed multiple key stages of VP88GFP redistribution and the dynamics of viral assembly site (VAS). Specifically, VP88GFP entry into and condensation in the VAS occurred within a 6-h duration, a similar duration was observed also for the release of VP88GFP-containing SGIV out of the cell. Taken together, VP088 is an excellent marker for visualizing the SGIV infection process. Our results provide new insight into macromolecular component recruitment and SGIV assembly.Electronic supplementary materialThe online version of this article (doi:10.1007/s13238-016-0292-3) contains supplementary material, which is available to authorized users.

Predicting the surface composition of a spray-dried particle by modelling component reorganization in a drying droplet

Properties of powders, such as flowability, reconstitution behaviour or particle adhesion, depend on the surface properties, which are related to the surface composition and environmental conditions. Many researchers reported redistribution of the feed components along a droplet radius during spray-drying of multicomponent food systems. This redistribution can be driven by the difference in the diffusivity of the components, component solubility, density, surface activity and hydrophobicity of components. The final composition on the surface of a dried particle is a resultant of all these material properties.This contribution presents an approach to estimate the surface composition of a particle formed during drying a multicomponent droplet. A continuum model of drying of a single droplet in a hot air stream was applied to predict the radial distribution of the components in the particle. The initial droplet consists of three components: water and two solutes, with different diffusion coefficients. In the model, the mass transfer is described by diffusion. The influences of the initial solid content and component ratio on the composition of the most outer layer of the formed particle were studied. An enrichment on the surface in the slowly diffusing component by 10–150% were predicted for different initial total solid contents, solid-based mass fractions of slowly diffusing component in the bulk and drying temperatures. Our model predicts that the initial ratio of the solid components has an impact on the surface composition only at low initial total solids content and that the drying air temperature has a weaker effect on the surface enrichment than the initial total solids content.