Role of RNA Motifs in RNA Interaction with Membrane Lipid Rafts: Implications for Therapeutic Applications of Exosomal RNAs

RNA motifs may promote interactions with exosomes (EXO-motifs) and lipid rafts (RAFT-motifs) that are enriched in exosomal membranes. These interactions can promote selective RNA loading into exosomes. We quantified the affinity between RNA aptamers containing various EXO- and RAFT-motifs and membrane lipid rafts in a liposome model of exosomes by determining the dissociation constants. Analysis of the secondary structure of RNA molecules provided data about the possible location of EXO- and RAFT-motifs within the RNA structure. The affinity of RNAs containing RAFT-motifs (UUGU, UCCC, CUCC, CCCU) and some EXO-motifs (CCCU, UCCU) to rafted liposomes is higher in comparison to aptamers without these motifs, suggesting direct RNA-exosome interaction. We have confirmed these results through the determination of the dissociation constant values of exosome-RNA aptamer complexes. RNAs containing EXO-motifs GGAG or UGAG have substantially lower affinity to lipid rafts, suggesting indirect RNA-exosome interaction via RNA binding proteins. Bioinformatics analysis revealed RNA aptamers containing both raft- and miRNA-binding motifs and involvement of raft-binding motifs UCCCU and CUCCC. A strategy is proposed for using functional RNA aptamers (fRNAa) containing both RAFT-motif and a therapeutic motif (e.g., miRNA inhibitor) to selectively introduce RNAs into exosomes for fRNAa delivery to target cells for personalized therapy.     

One-step methods for retarded differential equations with parameters

In this paper we develop a class of one-step methods combined with iterative methods to approximate the solution of retarded differential equations with parameters. The convergence theorems are established including the estimation of errors. Some methods are illustrated by three numerical examples.     

Initial cutting conditions by abrasive grain fixed flexibly

In the paper, the initial cutting conditions by an abrasive grain fixed flexibly have been described. These conditions have been determined by incision angle at the beginning of machining zone as well as the occurring phenomena resulting from a mechanical cooperation of abrasive grain with machined material. It has been revealed that the incision angle may affect the direction of changes of roughness of the smoothed surface, making it possible to forecast this output magnitude. The dependences of this angle on the machining parameters have been derived for the conditions of forward and backward machining. They make it possible to choose these parameters as a rationale for the smoothing effects of finishing. The presented considerations and the conclusions coming out of them have been verified by experiment, and some exemplary proofs of these cognitive actions are described in the paper.     

Alternation on rolling contact properties of steel due to magnetic field

This paper describes the effects of magnetic field on rolling contact performance of steel/steel disc couple and presents an investigation into the mechanisms governing these effects by applying contact mechanics and magnetism theory.The tests were carried out in disc-on-disc contact configuration under 1.1 T [Tesla] of horizontal static magnetic fields created by permanent magnets in three different orientations.Wear amounts were decreased in the magnetic fields and there was difference in magnetic field orientation. For the characteristic of the surface, results of scanning electron microscope observations point out that finer wear particles and smoother worn surfaces are produced in the presence of magnetic field. The smoother surfaces are also confirmed by surface roughness measurements. For the generation of the finer wear particles, it is considered that subsurface crack initiation point is moved toward the surface due to magnetic field.The effect of magnetic field is considered by calculating the number of cycles required to generate wear particles and the cycle was reduced due to the presence of magnetic field.It is considered, from views of contact mechanics and magnetism theory, that domain walls near the contact region are caught by dislocations when the specimen is magnetised and part of the energy for magnetisation activates the dislocation movement resulting in crack initiation.     

Alkali-metal promoted rhodium-on-alumina catalysts for nitrous oxide decomposition

Catalytic activity of γ-alumina supported rhodium catalysts in nitrous oxide decomposition into dinitrogen and dioxygen has been determined, the total conversion being reached at 450 °C. Rhodium is present at alumina surface in three forms: metal particles, Rh₂O₃ and rhodium zero valent atoms interacting with oxygen ions at the metal/support interface. Linear dependence of the catalytic activity on rhodium dispersion has been found. Deposition of alkali metal cations: Li, Na, K and Cs as promoters at the surface of alumina results in a considerable increase of rhodium dispersion and hence catalytic activity. The effect of promoters depends strongly on the speciation of alkali metals and rhodium used in the preparation of the catalyst. Both alkali metal cations and rhodium compete for the same OH groups at the alumina surface. The electronegativity of alkali metal oxides is much greater than that of alumina and their deposition increases the negative charge of surface oxide ions hindering the diffusion of rhodium and preventing the growth of its larger particles.     

The influence of the concentration of the quench gas on the count rate effect in proportional counters

The count rate dependent shift of pulse height in cylindrical proportional counters has been measured for Kr/iso-pentane, and Kr/cyclohexane mixtures. The effect of various concentrations of quench vapour on this shift has been investigated. A very rapid decrease of this shift has been found for a concentration of the admixture c ～ 1.5% in comparison with a smaller concentration. The theoretical explanation for this dependence is also presented.     

Nutritive quality of the alkaloid-poor Washington lupin (Lupinus polyphyllus lindl var SF/TA) as a potential protein crop

Abstract : An alkaloid-poor line of Washington lupin (Lupinus polyphyllus Lindl var SF/TA) was developed in an experiment started in 1982. The nutritive quality (alkaloid content, protein and amino acids, fat and fatty acids. macro- and micronutrients, fibre, sugars) yields, and seed quality of this line were studied. The results show that the total alkaloid content was low and varied in different seeds from 226 μg g^?1 to 366 μg g^?1 of dry matter. The main alkaloid was lupanine, but 16 other alkaloids (including sparteine and gramine) were also present. The var SF/TA cannot yet be used for human nutrition without processing although it would be a valuable protein crop. The results confirm that seeds which look different also vary in chemical composition.     

The properties of soldering mask hardened by means of UV using acrylate and methacrylate oligomers

The properties of soldering masks based on epoxyacrylic, epoxymethacrylic esters, and monomers: 2-ethylhexyl acrylate, triethylene glycol dimethacrylate, and triethylene glycol phthalate dimethacrylate have been described. The thixotropic properties, printability, adhesion to the surface, and resistance to soldering have been determined. © 1995 John Wiley & Sons, Inc.