Origin of the Magnetic Exciton in the van der Waals Antiferromagnet NiPS_{3}.

An ultrasharp photoluminescence line intimately related to antiferromagnetic order has been found in NiPS_{3}, a correlated van der Waals material, opening prospects for magneto-optical coupling schemes and spintronic applications. Here we unambiguously clarify the singlet origin of this excitation, confirming its roots in the spin structure. Based on a comprehensive investigation of the electronic structure using angle-resolved photoemission and q-dependent electron energy loss spectroscopy as experimental tools we develop, in a first step, an adequate theoretical understanding using density functional theory (DFT). In a second step the DFT is used as input for a dedicated multiplet theory by which we achieve excellent agreement with available multiplet spectroscopy. Our Letter connects the understanding of the electronic structure and of optical processes in NiPS_{3} and related materials as a prerequisite for further progress of the field.

Dispersion of electron-phonon resonances in one-layer graphene and its demonstration in micro-Raman scattering.

In the present work, we used Raman spectroscopy as sensitive tool for characterization of dispersion of electron-phonon resonances in one-layer graphene. We analyzed Stokes and anti-Stokes components of the Raman spectra to investigate the temperature dependence of the graphene G-band on the power of exciting radiation. Appearance and drastic intensity increase of zone-edge D-like modes caused by introduction of structural defects and/or deformations in the graphene layer were observed in the Raman spectra at high powers of excitation. We investigated phonon dispersion of one-layer graphene for iTO phonon branch at K point along K-M direction, which is involved in double-resonance Raman scattering. Raman dispersion slope of D-band is in good agreement with results of theoretical calculations based on the Green's functions approach based on the screened electron-electron interaction. Deviation of the experimental iTO phonon frequency from the linear dependence on excitation energy was observed at excitation E(exc) = 3.81 eV. Self-consistent classification of phonon states according to the symmetry for all dispersion branches of one-layer graphene was carried out.

Low- and high-frequency intermediate modes with step-like dispersion in resonance Raman scattering of carbon nanotubes.

Resonance Raman spectra of mixture of single-wall carbon nanotubes were investigated in details. The diameter distribution of the investigated nanotubes was estimated from the experimental frequencies of radial breathing modes. Two series of two-phonon lines revealing step-like behavior with excitation energy as well as non-dispersive single-phonon lines were registered in the intermediate frequency range 200-1200 cm(-1). Observed Raman lines were analyzed and their assignment to particular phonons was carried out. Step-like dispersive high intermediate-frequency modes in the range of 720-1000 cm(-1) are attributed to resonance two-phonon processes with combinations of optical and acoustical modes Low intermediate-frequency modes in the range of 300-650 cm(-1), also revealing step-like behavior, are attributed to resonance two-phonon processes with combinations of flexural optical and acoustical modes.

Mass exchange in an experimental new-generation life support system model based on biological regeneration of environment.

An experimental model of a biological life support system was used to evaluate qualitative and quantitative parameters of the internal mass exchange. The photosynthesizing unit included the higher plant component (wheat and radish), and the heterotrophic unit consisted of a soil-like substrate, California worms, mushrooms and microbial microflora. The gas mass exchange involved evolution of oxygen by the photosynthesizing component and its uptake by the heterotroph component along with the formation and maintaining of the SLS structure, growth of mushrooms and California worms, human respiration, and some other processes. Human presence in the system in the form of "virtual human" that at regular intervals took part in the respirative gas exchange during the experiment. Experimental data demonstrated good oxygen/carbon dioxide balance, and the closure of the cycles of these gases was almost complete. The water cycle was nearly 100% closed. The main components in the water mass exchange were transpiration water and the watering solution with mineral elements. Human consumption of the edible plant biomass (grains and roots) was simulated by processing these products by a unique physicochemical method of oxidizing them to inorganic mineral compounds, which were then returned into the system and fully assimilated by the plants. The oxidation was achieved by "wet combustion" of organic biomass, using hydrogen peroxide following a special procedure, which does not require high temperature and pressure. Hydrogen peroxide is produced from the water inside the system. The closure of the cycle was estimated for individual elements and compounds. Stoichiometric proportions are given for the main components included in the experimental model of the system. Approaches to the mathematical modeling of the cycling processes are discussed, using the data of the experimental model. Nitrogen, as a representative of biogenic elements, shows an almost 100% closure of the cycle inside the system. The proposed experimental model of a biological system is discussed as a candidate for potential application in the investigations aimed at creating ecosystems with largely closed cycles of the internal mass exchange. The formation and maintenance of sustainable cycling of vitally important chemical elements and compounds in biological life support systems (BLSS) is an extremely pressing problem. To attain the stable functioning of biological life support systems (BLSS) and to maintain a high degree of closure of material cycles in than, it is essential to understand the character of mass exchange processes and stoichiometnc proportions of the initial and synthesized components of the system.

[Automated processing of electrophysiologic signals]. / Avtomaticheskii analiz élektrofiziologicheskikh signalov.

The paper outlines a diagram of a multichannel analyzer of electrophysiological signals while are significantly non-stationary (such as those of electroencephalograms, myograms, etc.), by using a method based on the ranging procedure by the change-over points which may be the points of infection, impaired locality, minima, maxima, discontinuity, etc.

Beta-subunit of bovine rod photoreceptor cGMP phosphodiesterase. Comparison with the phosphodiesterase family.

A group of cDNA clones encoding the beta-subunit of bovine rod photoreceptor cGMP phosphodiesterase were isolated for structural analysis. The encoded polypeptide has 853 residues with a calculated molecular mass of 98 kDa. The beta-subunit is 72% identical to the rod cGMP phosphodiesterase alpha-subunit. Like the alpha-subunit and the cone alpha'-subunit, the beta-subunit belongs to the family of phosphodiesterase genes. The beta- and alpha-subunits are more similar to each other than either is to the cone alpha'-subunit, suggesting either that the beta- and alpha-subunits diverged more recently or that their divergence was restrained by the rod functional environment.

[Cyclic GMP phosphodiesterase from bovine retina. Amino acid sequence of beta-subunit and nucleotide sequence of corresponding cDNA]. / Fosfodiésteraza tsiklicheskogo GMP iz setchatki byka. Aninokislotnaia posledovatel'nost' beta-sub''edinitsy i nukleotidnaia posledovatel'nost' sootvetstvuiushchei kDNK.

Primary structure of beta-subunit of the cyclic GMP phosphodiesterase has been determined by the parallel analysis of the protein amino acid sequence and the corresponding cDNA nucleotide sequence. The beta-subunit contains 852 amino acid residues, its molecular mass is 98291 Da. A significant homology is found between beta- and alpha-subunit of the cGMP phosphodiesterase.

Cyclic GMP phosphodiesterase from bovine retina. Amino acid sequence of the alpha-subunit and nucleotide sequence of the corresponding cDNA.

The alpha-subunit primary structure of cyclic GMP phosphodiesterase has been determined by parallel analysis of the protein amino acid sequence and the corresponding cDNA nucleotide sequence. The enzyme alpha-subunit contains 858 amino acid residues, its N-terminal amino group being acetylated. The partial primary structure of the enzyme beta-subunit has also been elucidated. A significant homology has been found between the alpha- and beta-subunits of cGMP phosphodiesterase.

Cyclic GMP phosphodiesterase from cattle retina. Amino acid sequence of the gamma-subunit and nucleotide sequence of the corresponding cDNA.

The primary structure of the gamma-subunit of cyclic GMP phosphodiesterase was determined by parallel analysis of the amino acid sequence of the protein and nucleotide sequence of the corresponding cDNA. The enzyme gamma-subunit contains 87 amino acid residues, its N-terminal amino group being acetylated.

[Primary structure of the E. coli DNA region preceding the tryptophan operon genes]. / Pervichnaia struktura uchastka DNK E. coli, predshestvuiushchego genam triptofanovogo operona.

The nucleotide sequence of 1179 b.p. preceding the trp operon genes has been established. There are no open reading frames large enough to code for proteins containing more than 97 amino acid residues. In all cases the coding sequences do not contain the initiation codons. The determined sequence is concluded to represent an intercistronic region.

The primary structure of E. coli RNA polymerase, Nucleotide sequence of the rpoC gene and amino acid sequence of the beta'-subunit.

The primary structure of the E. coli rpoC gene (5321 base pairs) coding the beta'-subunit of RNA polymerase as well as its adjacent segment have been determined. The structure analysis of the peptides obtained by cleavage of the protein with cyanogen bromide and trypsin has confirmed the amino acid sequence of the beta'-subunit deduced from the nucleotide sequence analysis. The beta'-subunit of E. coli RNA polymerase contains 1407 amino acid residues. Its translation is initiated by codon GUG and terminated by codon TAA. It has been detected that the sequence following the terminating codon is strikingly homologous to known sequences of rho-independent terminators.

The primary structure of Escherichia coli RNA polymerase. Nucleotide sequence of the rpoB gene and amino-acid sequence of the beta-subunit.

The combined structural study of proteins and of their corresponding genes utilizing the methods of both protein and nucleotide chemistry greatly accelerates and considerably simplifies both the nucleotide and protein structure determination and, in particular, enhances the reliability of the analysis. This approach has been successfully applied in the primary structure determination of the beta and beta' subunits of Escherichia coli DNA-dependent RNA polymerase and of their structural genes, yielding a continuous nucleotide sequence (4714 base pairs) that embraces the entire rpoB gene, the initial part of the rpoC gene and the intercistronic region, together with the total amino acid sequence of the beta subunit, comprising 1342 residues, and the N-terminal sequence of the beta' subunit (176 residues).

Primary structure of Escherichia coli RNA polymerase nucleotide substitution in the beta subunit gene of the rifampicin resistant rpoB255 mutant.

The transducing phage lambda dsupM814 and the plasmid pIB1830 containing the wild-type rpoB gene have been constructed and the primary structure of the gene's central fragment has been established. In contrast with the wild-type, the gene of the rpoB255 mutant, whose primary structure has been published, was found to contain an A.T. leads to T.A. transversion entailing the substitution of a valine residue for the aspartic acid residue (516) of the wild-type beta subunit.