196 research outputs found
ABO, D Blood Typing and Subtyping Using Plug-Based Microfluidics
A plug-based microfluidic approach was used to perform
multiple agglutination assays in parallel without crosscontamination and using only microliter volumes of blood.
To perform agglutination assays on-chip, a microfluidic
device was designed to combine aqueous streams of
antibody, buffer, and red blood cells (RBCs) to form
droplets 30-40 nL in volume surrounded by a fluorinated
carrier fluid. Using this approach, proof-of-concept ABO
and D (Rh) blood typing and group A subtyping were
successfully performed by screening against multiple
antigens without cross-contamination. On-chip subtyping
distinguished common A1 and A2
RBCs by using a lectinbased dilution assay. This flexible platform was extended
to differentiate rare, weakly agglutinating RBCs of A
subtypes by analyzing agglutination avidity as a function
of shear rate. Quantitative analysis of changes in contrast
within plugs revealed subtleties in agglutination kinetics
and enabled characterization of agglutination of rare blood
subtypes. Finally, this platform was used to detect bacteria, demonstrating the potential usefulness of this assay
in detecting sepsis and the potential for applications in
agglutination-based viral detection. The speed, control,
and minimal sample consumption provided by this technology present an advance for point of care applications,
blood typing of newborns, and general blood assays in
small model organisms
Self-Similar Random Processes and Infinite-Dimensional Configuration Spaces
We discuss various infinite-dimensional configuration spaces that carry
measures quasiinvariant under compactly-supported diffeomorphisms of a manifold
M corresponding to a physical space. Such measures allow the construction of
unitary representations of the diffeomorphism group, which are important to
nonrelativistic quantum statistical physics and to the quantum theory of
extended objects in d-dimensional Euclidean space. Special attention is given
to measurable structure and topology underlying measures on generalized
configuration spaces obtained from self-similar random processes (both for d =
1 and d > 1), which describe infinite point configurations having accumulation
points
Genetic polymorphism of high-molecular-weight glutenin subunit loci in bread wheat varieties in the Pre-Ural steppe zone
High-molecular-weight glutenins play an important role in providing high baking qualities of bread wheat grain. However, breeding bread wheat for this trait is very laborious and, therefore, the genotyping of variety samples according to the allelic composition of high-molecular-weight glutenin genes is of great interest. The aim of the study was to determine the composition of high-molecular-weight glutenin subunits based on the identification of the allelic composition of the Glu-1 genes, as well as to identify the frequency of the Glu-1 alleles in bread wheat cultivars that are in breeding work under the conditions of the Pre-Ural steppe zone (PSZ). We analyzed 26 winter and 22 spring bread wheat varieties from the PSZ and 27 winter and 20 spring varieties from the VIR collection. Genotyping at the Glu-A1 locus showed that the Ax1 subunits are most common in winter varieties, while the predominance of the Ax2* subunits was typical of spring varieties and lines. In the Glu-B1 locus, the predominance of alleles associated with the production of the Bx7 and By9 subunits was revealed for both winter and spring varieties. In the case of the Glu-D1 gene, for all the wheat groups studied, the composition of the Dx5+Dy10 subunits was the most common: in 92.3 % of winter and 68.2 % of spring PSZ accessions and in 80 % of winter and 55 % of spring VIR accessions. The analysis of genotypes showed the presence of 13 different allelic combinations of the Glu-A1, Glu-B1, Glu-D1 genes in the PSZ varieties, and 19 combinations in the VIR varieties. The b b/al/с d allelic combination (Ax2* Вх7+Ву8/8*/9 Dx5+Dy10) turned out to be the most common for the PSZ spring varieties and lines, while for the PSZ winter accessions it was a с d (Ax1 Вх7+By9 Dx5+Dy10); the b с a and b с d genotypes (Ax2* Вх7+Ву9 Dx2+Dy12 and Ax2* Вх7+Ву9 Dx5+Dy10, respectively) occur with equal frequency among the VIR spring accessions; in the group of VIR winter varieties, the combination of the a b/ al d alleles (Ax1 Вх7+Ву8/8* Dx5+Dy10) prevails. The most preferred combination of alleles for baking qualities was found in the spring variety ‘Ekaterina’ and winter varieties ‘Tarasovskaya 97’, ‘Volzhskaya S3’, as well as in lines k-58164, L43510, L43709, L-67, L-83, which are recommended for further breeding programs to improve and preserve baking qualities in the conditions of the Pre-Ural steppe zone
Support and Catalyst for the Alkylation of Benzene by Ethylene Process
A method for preparation of a spherical alumina support with preset porous structure for a catalyst of benzene alkylation with ethylene has been developed. The process of the support manufacture has been adjusted in a pilot installation, and an industrial installation for production of alumina support for the alkylation catalyst has been designed and built at the Shevchenko Plastics Plant (Aktau, Kazakhstan)
Structural Changes of Mo/ZSM-5 Catalysts During the Methane Dehydroaromatization
The structure changes of Mo/ZSM-5 catalysts with different Mo content (2 and 10 wt. % Mo) and Si/Al atomic ratio (17, 30 and 45) during the methane dehydroaromatization have been investigated by X-ray powder diffractometry, N2 adsorption and transmission electron microscopy. The treatment of Mo/ZSM-5 catalysts in reducing atmosphere (CH4 or H2) at about 700 oC promotes development of mesoporous system. The pores are open to the exterior of the zeolite grain and have an entrance diameter of ~ 4-10 nm. It is proposed that mesopore formation in Mo/ZSM-5 catalyst is connected with the dealumination of zeolite. The mesopore formation in the parent H-ZSM-5 zeolite by NaOH treatment does not improve the activity of /ZSM-5 catalyst
Direct Catalytic Reduction of SO2 by CH4 over Fe-Mn Catalysts Prepared by Granulation of Ferromanganese Nodules
The chemical, textural, structural and strength properties of ferromanganese nodules and granulated Fe-Mn catalysts containing such nodules were studied. It was found that the granulated catalysts have a developed pore structure, which is close to that of the starting material, and surpass the starting material in strength parameters. The catalysts were tested in desulfurization by methane at a stoichiometric ratio SO2/CH4 = 2. The testing showed that Fe-Mn catalysts with the oxide or sulfide form of active components are active in desulfurization by methane and can selectively reduce SO2 with a conversion above 80%
Deactivation and Regeneration of Mo/ZSM-5 Catalysts for Methane Dehydroaromatization
The methane dehydroaromatization (DHA) was studied over a series of impregnated Mo/ZSM-5 catalysts with different molybdenum contents (1-10 wt.%). It was shown that total methane conversion was decreased by 30% during 12 h of DHA reaction. The benzene formation rate was increased from 0.5 to 13.9 mol C6H6/(gMo·s) when the molybdenum content in the catalyst was lowered from 10 to 1 wt.%. The deactivated Mo/ZSM-5 catalysts were studied by a group of methods: N2 adsorption, XRD, TGDTA, HRTEM and XPS. The content and condensation degree (C/H ratio) of the carbonaceous deposits was found to increase with an increase of either of the following parameters: molybdenum content (1-10 wt.%), reaction temperature (720-780 °C), space velocity (405-1620 h-1), reaction time (0.5-20 h). The stability of Mo/ZSM-5 catalysts in reaction-regeneration cycles was better when the time on stream was shorter. The regeneration conditions of deactivated Mo/ZSM-5 catalysts providing their stable operation under multiple reaction-regeneration cycles have been selected
Indigenous Bacteria from the Gut Microbiota Regulate Host Serotonin Biosynthesis
The gastrointestinal (GI) tract contains much of the body’s serotonin (5-hydroxytryptamine, 5-HT), but mechanisms controlling the metabolism of gut-derived 5-HT remain unclear. Here, we demonstrate that the microbiota plays a critical role in regulating host 5-HT. Indigenous spore-forming bacteria (Sp) from the mouse and human microbiota promote 5-HT biosynthesis from colonic enterochromaffin cells (ECs), which supply 5-HT to the mucosa, lumen, and circulating platelets. Importantly, microbiota-dependent effects on gut 5-HT significantly impact host physiology, modulating GI motility and platelet function. We identify select fecal metabolites that are increased by Sp and that elevate 5-HT in chromaffin cell cultures, suggesting direct metabolic signaling of gut microbes to ECs. Furthermore, elevating luminal concentrations of particular microbial metabolites increases colonic and blood 5-HT in germ-free mice. Altogether, these findings demonstrate that Sp are important modulators of host 5-HT and further highlight a key role for host-microbiota interactions in regulating fundamental 5-HT-related biological processes
Highly Dispersed Palladium on Carbon Nanofibers for Hydrogenation of Nitrocompounds to Amines
The effect of palladium dispersion and nature of the support on catalytic performance in hydrogenation of nitrobenzene to aniline was studied. It was shown that the type of the support and modification of palladium with phosphorus make it possible to stabilize highly dispersed (1.5-2 nm) palladium particles in the metallic state, thus increasing the efficiency of new catalysts
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