[Differential Expression of a Foreign Gene in Arabidopsis Mitochondria In Organelle].

Genetic transformation of higher eukaryote mitochondria in vivo is an unresolved and important problem. For efficient expression of foreign genetic material in mitochondria, it is necessary to select regulatory elements that provide a high level of transcription and transcript stability. This work is aimed at studying the effectiveness of regulatory elements of mitochondrial genes flanking exogenous DNA using the phenomenon of natural competence of plant mitochondria. For this purpose, genetic constructs carrying the GFP gene under the control of the promoter regions of the RRN26 or COX1 genes and one of the two 3'-untranslated regions (3'-UTR) of mitochondrial genes were imported into isolated Arabidopsis mitochondria, followed by transcription in organello. It was shown that the level of GFP expression under the control of promoters of the RRN26 or COX1 genes in organello correlates with the level of transcription of these genes observed in vivo. At the same time, the presence of the tRNA^(Trp) sequence in the 3'-UTR leads to a higher level of the GFP transcript than the presence in this region of the 3'-UTR of the NAD4 gene containing the binding site of the MTSF1 protein. The results we obtained open prospects for creating a system for efficient transformation of the mitochondrial genome.

Carbon nanotubes for polarization sensitive terahertz plasmonic interferometry.

We report on helicity sensitive photovoltaic terahertz radiation response of a carbon nanotube made in a configuration of a field-effect transistor. We find that the magnitude of the rectified voltage is different for clockwise and anticlockwise circularly polarized radiation. We demonstrate that this effect is a fingerprint of the plasma waves interference in the transistor channel. We also find that the presence of the helicity- and phase-sensitive interference part of the photovoltaic response is a universal phenomenon which is obtained in the systems of different dimensionality with different single-particle spectrum. Its magnitude is a characteristic of the plasma wave decay length. This opens up a wide avenue for applications in the area of plasmonic interferometry.

Terahertz plasmonic detector controlled by phase asymmetry.

We demonstrate that a phase difference between terahertz signals coupled to the gate and source and gate and drain terminals of a field effect transistor (a TeraFET) induces a plasmon-assisted DC current, which is dramatically enhanced in the vicinity of plasmonic resonances. We describe a TeraFET operation with identical radiation amplitudes at the source and drain antennas but with a phase-shift-induced asymmetry. In this regime, the TeraFET operates as a tunable resonant polarization-sensitive plasmonic spectrometer, operating in the sub-terahertz and terahertz ranges of frequencies. We also propose an effective scheme of a phase-sensitive homodyne detector operating in this phase-asymmetry mode, which allows for a dramatic enhancement of the response. These regimes can be implemented in different materials systems, including silicon. The p-diamond TeraFETs could support operation in the 200 to 600 GHz atmospheric windows, which is especially important for beyond 5G communication systems.

[Proteus adhesion to intestinal epithelium]. / Adgeziia proteev k kishechnomu épiteliiu.

The adhesive properties of Proteus strains isolated from different sources have been studied under conditions similar to the real interaction of microorganisms with the epithelial cells of intestine. A comparison of the adhesive properties of Proteus and of colon Bacillus has shown that the value of the strong adhesion to the mucosa of Proteus isolated under enterocolitis at the same bulk concentrations of the infectious suspension is 2-3 order less than that of E. coli. The adhesion of Proteus to the surface of epithelial cells begins at bulk concentrations exceeding those for the colon Bacillus by 3-4 orders. Besides, a toxic effect of number of freshly isolated Proteus strains on the epithelial cells of intestine mucosa is observed. Strains isolated from patients with diarrhea and from environment differed from each other in the studied criteria. A conclusion is drawn that at the initial stage of the interaction with the intestine mucosa the Proteus strains differ considerably from the indigenous strain of the colon Bacillus in the ability to colonize the epithelial surface.