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Here, we have thoroughly studied the effect of chemistry of graphene derivatives on the composition of N-species after N-doping with the help of core-level spectroscopy techniques. The modulation of the N-species by tailoring the functionalization and atomic structure of graphene derivatives prior to chemical N-doping is experimentally demonstrated for the first time. The large extent of non-terminated or phenol-functionalized graphene edges is found to facilitate the formation of pyridinic nitrogen with its relative content exceeding 72%. In turn, the predominant decoration by the pyrazolic moieties is shown for the perforated and carboxyl-derived graphene layers. The thermal annealing at moderate temperatures of ca.345 °C is shown to equally readjust the composition of N-species in graphene derivatives regardless of their chemistry, nanostructure, and the initial distribution of the N-species. Further examination of N K-edge X-ray absorption spectra (XAS) pointed out that the oxidation of the graphene layer governs the manifestation of the π∗ resonances and configuration of the σ∗ resonance. As a result, a set of facile methods to synthesize graphene derivatives with the desired type of the embedded nitrogen species for the optoelectronic and catalytic applications are proposed and crucial features of their identification using core-level spectroscopy techniques are emphasized.

A double holmium-silver sulfate was obtained for the first time. The temperature intervals for the formation and stability of the compound were determined by differential scanning calorimetry. The crystal structure of AgHo(SO4)2 was determined by Rietveld method. The X-ray diffraction (XRD) analysis showed that the compound crystallizes in the monoclinic syngony, space group P21/m, with the unit cell parameters a = 4.71751 (4) A, b = 6.84940 (6) A and c = 9.89528 (9) A, β = 95.1466 (4)°, V = 318.448 (5) A3, Z = 2, RB = 1.55 %, T = 303 K. Two types of sulfate tetrahedra were found in the structure, which significantly affected the spectral properties in the infrared range. In the temperature range of 143−703 K, a negative thermal expansion along the b direction accompanied by a positive thermal expansion along the a and c directions was observed. It was established that negative thermal expansion is the result of the deformation of sulfate tetrahedra, which is affected by the movement of holmium and silver atoms. The excitation in the blue spectral range (457.9 nm) produces a luminescence in light blue (489 nm), green (545 nm) and red (654 nm) spectral ranges, and the latter two were of comparable intensity that is favorable for WLED sources. The observed luminescent band distribution is ascribed to the specific crystal field at Ho3+ ion sites rather than a variation of radiationless probability.

Back-contact modification using a 10-nm ZnS layer in CZTSSe-based solar cell can play a crucial role in improving photovoltaic conversion efficiency. An ultrathin layer of ZnS is deposited over Mo-coated soda lime glass substrate before depositing CZTSSe using sputtering. The crystal structure of deposited CZTSSe thin films over ZnS is recognized as (112)-oriented, polycrystalline in nature, and free from the presence of any secondary phases such as Cu2(S,Se) or Zn(S,Se). The bandgap of CZTSSe thin films deposited over ultrathin ZnS is observed to increase from 1.49 (deposited over Mo directly) to 1.58 eV at room temperature, as determined by spectroscopic ellipsometry. In addition, numerical simulation has been performed using SCAPS software. The impact of ZnS layer has been simulated by using the defects in the absorber and at the interface of ZnS/CZTSSe. The simulated results have been validated with experimentally fabricated CZTSSe device. Simulated device with ZnS intermediate layer is observed to give rise to a photovoltaic conversion efficiency of 15.2%.

A comparison was made of the physiological activity of brassinosteroids (BS) of different chemical structures—lactone-containing 24-epibrassinolide (EBL) and ketone-containing brassinosteroid 24-epicastasterone (ECS)—during dark aging of cut barley (Hordeum vulgare L.) leaves. The functional state of the photosynthetic apparatus, the amount of photosynthetic pigments, the content of lipid peroxidation products, and gene expression of HvS40 (senescence marker) were assessed. The separated barley leaves were incubated on solutions of EBL and ECS in the concentration range of 0.01–1 µM in Petri dishes on filter paper. Synthetic cytokinin 6-benzylaminopurine (BAP) at a 10 μM concentration was used as a positive control, and distilled water was used as a negative control. Petri dishes with leaves were kept in the dark for 5 days. Measurements of the analyzed parameters were carried out on the first, third, and fifth days from the beginning of incubation, mainly in the middle part of the leaf plate. ECS at a concentration of 1 μM reduced oxidative stress by the fifth day of incubation to a greater extent than EBL at a similar concentration. Regarding maintenance of chlorophyll a (Chl a) levels, 24-epicastasterone (1 μM) was more effective than 24-epibrassinolide. It was shown that exogenous brassinosteroids showed a protective effect on the main photochemical processes of the second photosystem during aging of barley leaves. Moreover, when assessing the coefficient of nonphotochemical quenching (qN), indicators of regulated (Y(NPQ)) and nonregulated (Y(NO)) energy dissipation, the ECS showed a more pronounced protective effect for the second photosystem compared to EBL. It was found that treatment with brassinosteroids reduced the level of gene expression of HvS40, a senescence marker on the fifth day of incubation, which was especially characteristic for the ketone-containing brassinosteroid. Thus, it can be concluded that the ketone-containing brassinosteroid not only exhibits high biological activity but, in terms of a number of parameters, is also more effective than the lactone-containing brassinosteroid in reducing the damage caused by aging.

Double perovskite ceramics Sr2FeMoO6–δ having different amount of antisite disordering and oxygen content are prepared by the solid-phase reaction method using SrFeO2.52(3) and SrMoO4 initial reagents. X-ray and neutron diffraction techniques are used to estimate a modification in the structural parameters as a function of oxygen content and B–site cationic ordering. Reduction of oxygen content leads to an increase in the unit cell volume, which is mainly associated with an elongation of c –parameter of the tetragonal unit cell and relative expansion of the chemical bonds between Mo/Fe ions and apical oxygen ions. Superstructural ordering observed for the compounds causes a decrease in the unit cell volume, which is accompanied by a reduction in the length of the Mo/Fe – O bonds, located in the basal plane of oxygen octahedra. This modification of the unit cell parameters notably affects a character of the exchange interactions formed between B–site ions thus allowing to control magnetic and transport properties of Sr2FeMoO6–δ ceramics. It is found that comprehensive approach allows a consistent understanding of much debated structural/magnetic behaviors of double perovskite Sr2FeMoO6–δ systems, opening a venue for designing reliable devices based on the half-metallic double perovskite materials.

LiCoPO4 was synthesized in a short time by a microwave-assisted solvothermal technique at 220°C. The as-prepared samples are characterized as belonging to the Pn21a symmetry group, having poor electrochemical performance, and low specific capacity around 30 mAh/g. Further, activation at 700°C under air and argon increased the specific capacity to 57 mAh/g and 55 mAh/g, respectively. The local atomic and electronic structure of the samples before and after annealing was studied using x-ray absorption spectroscopy (XAS). The activation under air and Ar led to a phase transition from the Pn21a space group to the Pnma space group without changes in the Co oxidation state. Therefore, using myristic acid as a source for carbon coating, we found that there were no specific requirements for the activation atmosphere.

We analyze the presence of a microwave neutral-line-associated source (NLS) in a super-active region NOAA 12673, which produced a number of geo-effective events in September 2017. To estimate the NLS position, we use data from the Siberian Radioheliograph in a range 4–8 GHz and from the Nobeyama Radioheliograph at 17 GHz. Calculation of the coronal magnetic field in a non-linear force-free approximation has revealed an extended structure consisting of interconnected magnetic flux ropes, located practically along the entire length of the main polarity separation line of the photospheric magnetic field. NLS is projected into the region of the strongest horizontal magnetic field, where the main energy of this structure is concentrated. During each X-class flare, the active region lost magnetic helicity and became a CME source.

Bromination of (2E)-3-aryl(hetaryl)-2-[4-aryl(hetaryl)-1,3-thiazol-2-yl]acrylonitriles proceeds regioselectively at the C5 atom of the thiazole ring with the formation of new (2E)-3-aryl(hetaryl)-2-[5-bromo-4-aryl(hetaryl)-1,3-thiazol-2-yl]acrylonitriles. The latter were alternatively obtained by the reaction of aldehydes, cyanothioacetamide, α-bromoketones and bromine in the presence of triethylamine in DMF. Structure of the key compounds was confirmed using 2D NMR spectroscopy and single crystal X-ray diffraction analysis.

A series of 3,4-diarylpyrrole-2-carboxamides was synthesized using the Barton—Zard reaction of nitrostilbenes with ethyl isocyanoacetate in the key stage. The antiproliferative properties of these compounds were studied on a sea urchin embryo model, as well as on 60 human tumor cell lines.

Phytohormones are known to play an important role in the regulation of chloroplast biogenesis. However, information on the pathways of hormonal signal perception by chloroplasts is limited. In order to analyze the possible mechanisms of hormone action, the response to abscisic acid (ABA) and cytokinin (CKs) treatment of Arabidopsis thaliana (L.) Heynh. scabra3-2 (sca3-2) and rpotmp mutants with defective genes for nuclear-encoded plastid RNA polymerases was studied. The reaction of the rpotmp mutant usually did not differ from the response of wild-type plants: trans-zeatin activated the accumulation of transcripts of genes encoding the transcription apparatus and genes encoded by the plastid genome, while ABA weakly suppressed their expression or had no significant effect. However, the steady-state levels of gene templates of the plastid-encoded RNA polymerase (PEP-A) enzyme complex in the rpotmp mutant were higher than in wild-type plants, probably due to a compensatory mechanism that allows the mutant to enhance PEP-dependent transcription in the absence of the RPOTmp enzyme. Dysfunction of the plastid RNA polymerase RPOTp enzyme in the sca3-2 mutant induced an altered hormonal response of the genes for plastid transcriptional complex and plastid-encoded genes in comparison with the response of wild-type plants. The absence of a significant up-regulating effect of CKs on the expression of genes encoding the transcription apparatus correlated with the retention of the steady-state levels of transcripts for chloroplast genes and plastid proteins. In addition, the sca3-2 mutant had an increased steady-state expression of genes for CK metabolism: IPT3, IPT5, and CKX5. However, the response to the inhibitory effect of ABA in this mutant, on the contrary, was more pronounced, which is possibly caused by the changes in the steady-state levels of the transcripts of a number of genes encoding of ABA signaling and metabolism proteins. Thus, changes in the expression of NEP (nuclear-encoded RNA polymerases) genes under the action of hormones can be transformed into activation or inhibition in the expression of chloroplast genes of nuclear or plastome coding, providing the regulation of chloroplast functions through the mechanisms of anterograde signaling.

Here, the synthesis of holey carbonylated (C-ny) graphene derivative and its application for gas sensing is demonstrated. The carbonylation of graphene oxide leads to the 3-fold increase in the concentration of carbonyl groups’ up to 9 at.% with a substantial elimination of other oxygen functionalities. Such a chemical modification is accompanied by the perforation of the graphene layer with the appearance of matrices of nanoscale holes, leading to corrugation of the layer and its sectioning into localized domains of the π-conjugated network. Combined with the predominant presence of carbonyls, granting the specificity in gas molecules adsorption, these features result in the enhanced gas sensing properties of C-ny graphene at room temperature with a selective response to NH3. Opposite chemiresistive response towards ammonia when compared to other analytes, such as ethanol, acetone, CO2, is demonstrated for the C-ny graphene layer both in humid and dry air background. Moreover, a selective discrimination of all of the studied analytes is further approached by employing a vector signal generated by C-ny multielectrode chip. Comparing the experimental results with the calculations performed in framework of density functional theory, we clarify the effect of partial charge transfer caused by water and ammonia adsorption on the chemiresistive response.

The reaction of cyanothioacetamide with aromatic aldehydes and 1,3-dicarbonyl compounds followed by aminomethylation or S-alkylation gave a series of heterocyclic derivatives with a 1,2,3,4-tetrahydropyridine or 1,4,5,6,7,8-hexahydroquinoline fragment. The resulting compounds were tested for analgesic activity in vivo. Some of the prepared compounds showed an antinociceptive effect superior to that of ketorolac in dynamics.

Here we show theoretically that a superposition of two Bessel-Gaussian (BG) beams with different topological charges (TC) and different scaling factors (radial components of the wave vectors) has the TC equal to that of the BG beam with the larger scaling factor. If the scaling factors of the BG beams are equal, then TC of the whole superposition equals TC of the BG beam with the larger (in absolute value) weight coefficient in the superposition (i.e. with larger power). If the constituent BG beams are also same-power, TC of the superposition equals the average TC of the two BG beams. Therefore, if the sum of TCs of both beams is odd, TC of the superposition is a half-integer number. In practice, however, TC is calculated over a finite radius circle and, hence, the half-integer TC for the degenerated case cannot be obtained. Instead of the half-integer TC, the lower of the two integer TCs is obtained. Numerical simulation reveals that if the weight coefficients in the superposition are slightly different, TC of the superposition is not conserved on propagation. In the near field and in the Fresnel diffraction zone, TC is equal to the highest TC of the two BG beams, while in the far field it is equal to the lower TC. What is more, TC changes its value from high to low not instantly, but continuously at some propagation distance. In the intermediate zone TC is fractional.

The stoichiometry and phase homogeneity of the kesterite type compound Cu2ZnSnS4 play a key role in its efficiency in solar cells. In this work, CuCl2, ZnCl2 and SnCl2 were applied as solvents in the Cu2ZnSnS4 crystal growth for the first time. The multiphase ingot was obtained by direct fusion of the stoichiometric batch composed of constituent elements. Compared to that, the material recrystallized in SnCl2 presented a single-phase Zn-rich kesterite with composition Cu1.94Zn1.06SnS4 and unit cell parameters of a = 5.4324(3) and c = 10.8383(2) A. The crystal structure of Cu1.94Zn1.06SnS4 was determined by single crystal X-ray diffraction analysis. The integral phase purity of the crystals grown with the use of the SnCl2 solvent was verified by powder X-ray diffraction analysis and Raman measurements. In the Raman spectrum, the FWHM value of the 337 cm−1 line was as low as 9.6 cm−1 that indicates the minimal lattice disorder.

The article proposes a new method for increasing the information content of the image by minimizing the errors of the optical system of a large telescope using the redistribution of errors over the image field. Variation of the parameters of the secondary mirror is carried out to solve the optimization problem of uniform distribution of aberrations over the image field of a large telescope using the example of a cryotelescope with a diameter of 12 m in the Zemax-EE package. The results of calculations of optical schemes by the traditional method and by the method of optimization of the errors of the radiation wavefront are presented. The advantages and disadvantages are considered.

Cultivation of Azotobacter vinelandii D-08 in media with molasses and distillery waste was shown to increase levansaccharase activity and levan biosynthesis. Levansaccharase also exhibited maximal activity when grown in a molasses medium, which correlated with the highest level of the polysaccharide synthesis. An additional fraction of high molecular weight levan (more than 1000 kDa) with a modified molecular structure (reduced contribution of double bond oscillations and decreased molecule hydration) was synthesized by bacteria, which resulted in a higher capacity for the binding of Na, Mg, S, Ca, and Fe in the cultivation medium. Cryogels based on polyvinyl alcohol and levan were capable of efficient maximal absorption of different ions at different times: copper (1 h), zinc (24 h), and cadmium (10 min), radioactive plutonium (4 h), and uranium (168 h). This suggests that they can be used as sorbents for wastewater treatment to eliminate heavy metals and radionuclides.

The theory of endosymbiotic origin of chloroplasts has become basal in present-day biology. In this regard, the emergence of eukaryotic photosynthesis has been established as a result of phagocytal capture of cyanobacteria by some ancestral eukaryotic cell. The phenomenon of endosymbiosis is an indispensable element of cell evolution theory. The process of endosymbiogenesis belongs to the crucial factors of biological progress that gave rise to astonishing diversity and complexity of the eukaryotic organisms. The modern theory of evolution is built on the joint base of the phenomena of endosymbiosis, parallel gene transfer, the theory of natural selection, and the data of phylogenomics. Ultimately, eukaryogenesis has integrated different supramolecular complexes in the cells, created the diversity of organelles, and has led to biosphere oxygenation and modern diversity of living forms.

1,6-Diamino-2-oxo-1,2,3,4-tetrahydropyridine-3,5-dicarbonitriles under the action of primary aliphatic amines and an excess of 37% formalin in ethanol were converted into 2,3,8,9-tetrahydro-6,10-methano[1,2,4]triazolo[1,5-a][1,5]diazocine-6,10(7H)-dicarbonitrile derivatives. At the same time, the Mannich reaction in the case of 1,6-diamino-4-aryl-2-oxo-1,2-dihydropyridine-3,5-dicarbonitriles proceeds ambiguously, and, depending on the conditions, gives either N-ethoxymethylation products or 1,2,4-triazolo[1,5-a]pyridine derivatives. In silico predictive analysis of the biological activity of new compounds was carried out.

Information about the surrounding atmosphere at a real timescale significantly relies on available gas sensors to be efficiently combined into multisensor arrays as electronic olfaction units. However, the array's performance is challenged by the ability to provide orthogonal responses from the employed sensors at a reasonable cost. This issue becomes more demanded when the arrays are designed under an on-chip paradigm to meet a number of emerging calls either in the internet-of-things industry or in situ noninvasive diagnostics of human breath, to name a few, for small-sized low-powered detectors. The recent advances in additive manufacturing provide a solid top-down background to develop such chip-based gas-analytical systems under low-cost technology protocols. Here, we employ hydrolytically active heteroligand complexes of metals as ink components for microplotter patterning a multioxide combinatorial library of chemiresistive type at a single chip equipped with multiple electrodes. To primarily test the performance of such a multisensor array, various semiconducting oxides of the p- and n-conductance origins based on pristine and mixed nanocrystalline MnOx, TiO2, ZrO2, CeO2, ZnO, Cr2O3, Co3O4, and SnO2 thin films, of up to 70 nm thick, have been printed over hundred μm areas and their micronanostructure and fabrication conditions are thoroughly assessed. The developed multioxide library is shown to deliver at a range of operating temperatures, up to 400 °C, highly sensitive and highly selective vector signals to different, but chemically akin, alcohol vapors (methanol, ethanol, isopropanol, and n-butanol) as examples at low ppm concentrations when mixed with air. The suggested approach provides us a promising way to achieve cost-effective and well-performed electronic olfaction devices matured from the diverse chemiresistive responses of the printed nanocrystalline oxides.

We investigate a multispiral phase plate (MSPP) with multiple centers of phase singularity arbitrarily located in the MSPP plane. Equations to describe the topological charge of an optical vortex in the initial plane immediately behind the MSPP and orbital angular momentum (OAM) normalized relative to the beam power are derived. The topological charge in the initial plane is found as a sum of the topological charges of all singularities if their centers are located inside a finite-radius circular aperture. If the phase singularity centers are partially located on the boundary of a circular diaphragm limiting the MSPP, the total topological charge is found as the sum of all singularities divided by 2. Total OAM that the vortex carries depends on the location of the singularity centers: the farther from the center of the plate the singularity center is located, the smaller is its contribution to the OAM. If all singularity centers are located on the boundary of the diaphragm limiting MSPP, then the OAM of the vortex beam equals zero, although in this case the topological charge of the beam is nonzero.

The participation of reactants undergoing a polarity inversion along a multicomponent reaction allows the continuation of the transformation with productive domino processes. Thus, indole aldehydes in Groebke-Blackburn-Bienaymé reactions lead to an initial adduct which spontaneously triggers a series of events leading to the discovery of novel reaction pathways together with direct access to a variety of linked, fused, and bridged polyheterocyclic scaffolds. Indole 3- and 4-carbaldehydes with suitable isocyanides and aminoazines afford fused adducts through oxidative Pictet-Spengler processes, whereas indole 2-carbaldehyde yields linked indolocarbazoles under mild conditions, and a bridged macrocycle at high temperature. These novel structures are potent activators of the human aryl hydrocarbon receptor signaling pathway.

Abstract De-etiolation or transition from etiolated growth (skotomorphogenesis) to photomorphogenesis is one of the most intriguing and intricate stages of plant ontogenesis. It comprises reprogramming of plant cell metabolism, reorganizing the operation of the hormonal system, and altering plant morphology. Dark growth in the soil mainly depends on phytohormones with gibberellins and brassinosteroids playing the leading role; on the soil surface, light as a major exogenous agent starts operating. It inhibits activity of the main repressor of photomorphogenesis (COP1) and regulators of transcription, which govern realization of gibberellin (DELLA) and brassinosteroid (BZR1/BES1) signals and activates trans-factors initiating transition to autotrophic nutrition (for instance, HY5). The strategy of etiolated growth consists in achieving a quick exposure to sunlight at the expense of active elongation of the stem. For transition to autotrophic nutrition, a plant must form a photosynthetic apparatus and protect itself from possible light injury. This review deals with the role of the main regulatory components ensuring etiolated growth and transition to photomorphogenic development.

Natural senescence of leaves is a regular physiological process subjected to a certain genetic program and controlled by various phytohormones. Cytokinins (CKs) play a crucial role in the leaf-senescence control being negative regulators of this process. We previously reported on the prolonged vegetative growth and the development of a double knockout ahk2ahk3 mutant of Arabidopsis thaliana Heynh. (L.) for the genes encoding CK receptors. According to the data of the transcriptomic analysis and real-time RT‑PCR of selected genes performed in this study, the delay of leaf senescence in ahk2ahk3 mutants is accompanied by enhanced (4–281-fold) expression of the group of SAUR (small auxin-up RNA) genes encoding auxin response proteins and by upregulation of the SSPP (senescence-suppressed protein phosphatase) gene, whose expression level significantly (137-fold) exceeded that in a wild-type transcriptome. Thus, it is quite possible that under significant inhibition of the CK signaling leaf senescence in Arabidopsis plants regulated via a compensatory mechanism connected with changes in the expression of the SAUR gene family and a certain pool of genes related to the auxin transport and signaling.

Curcumin is known to exist in three polymorphs (forms I, II, and III) in the solid state. The most common polymorph of curcumin (form I) is monoclinic in the space group P2/n, whereas the other two...

The recent data (2007–2018) on the synthesis of thieno[2,3-b]pyridines are summarized and systematized.

Using electronic beam lithography and reactive ion beam etching, a metalens is manufactured in a thin layer of amorphous silicon of a 130-nm depth, a 30-µm diameter, and a 633-nm focal length (equal to the illumination wavelength). The metalens is composed of 16 sectored subwavelength binary gratings with a 220-nm period. The uniqueness of this metalens is that when illuminated by left-handed circularly polarized light, it is capable of generating a left-handed circularly polarized vortex beam with a topological charge of 2, generating a second-order cylindrical vector beam when illuminated by linearly polarized light. Both for linear and circular incident polarization, an energy backflow is found to be generated in the vicinity of the tight focus. Transverse intensity distributions measured with a scanning near-field optical microscope near the focus of the metalens are in qualitative agreement with the intensity distributions calculated by the FDTD method. This confirms that a backward energy flow takes place at the focus of the metalens. A metalens generating an energy backflow near its focus is fabricated and characterized for the first time.

The sequential reaction of furfural with cyclic secondary amines and further with benzaldehyde and cyanoacetates affords new 2,4-dicyano-8-(R2N)-6-oxo-3-phenylbicyclo[3.2.1]-octane-2,4-dicarboxylates as rac-(1R,2R,3R,4S,5S,8R)-diastereomers. The structures of the reaction products were determined by X-ray diffraction.

A series of 73 ligands and 73 of their Cu+2 and Cu+1 copper complexes with different geometries, oxidation states of the metal, and redox activities were synthesized and characterized. The aim of the study was to establish the structure-activity relationship within a series of analogues with different substituents at the N(3) position, which govern the redox potentials of the Cu+2/Cu+1 redox couples, ROS generation ability, and intracellular accumulation. Possible cytotoxicity mechanisms, such as DNA damage, DNA intercalation, telomerase inhibition, and apoptosis induction, have been investigated. ROS formation in MCF-7 cells and three-dimensional (3D) spheroids was proven using the Pt-nanoelectrode. Drug accumulation and ROS formation at 40-60 μm spheroid depths were found to be the key factors for the drug efficacy in the 3D tumor model, governed by the Cu+2/Cu+1 redox potential. A nontoxic in vivo single-dose evaluation for two binuclear mixed-valence Cu+1/Cu+2 redox-active coordination compounds, 72k and 61k, was conducted.

New calix[4]resorcinols with four anthracene-ended triazolecontaining fragments as rctt- and rccc-diastereoisomers were obtained in two synthetic pathways, namely, by acidcatalyzed condensation of resorcinols with 4-{[1-(anthracen-9-ylmethyl)-1H-[1,2,3]triazol-4-yl]methoxy}benzaldehyde or by the click reaction of 9-(azidomethyl)anthracene with calix[4]resorcinols bearing four terminal acetylene moieties. The compounds obtained demonstrate dual emission in solid state with intensity of low energy band depending on calix[4]resorcinol conformation. The emission in solutions is dominated by anthracene bands, with rccc-isomer showing additional low energy band.

Nitrilotris(methylenephosphonic)acid N[CH2P(O)(OH)2]3 (H6L) reacts with zinc oxide in an aqueous medium to give a poorly soluble polymeric crystalline salt (ZnH4L)n. The reaction proceeds through the intermediate formation of a soluble monomer complex ZnH4L. The water-soluble amorphous forms of the coordination compound used as microfertilizers were obtained by treatment of a suspension of this salt with 2-aminoethanol, 2-amino-2-(hydroxymethyl)propane-1,3-diol, 2,2′-(ethylenedioxy)bis(ethylamine). p-Aminobenzoic acid H2NC6H4COOH reacts in an aqueous solution with hexabasic nitrilotrimethylenephosphonic acid, as well as with the monomeric complex ZnH4L, giving crystals of bis(4-carboxyphenylaminium) nitrilotris(methylenephosphonate) dihydrate H4L2− · 2(H3N-C6H4-COOH)+ · 2H2O. The compounds were investigated by elemental analysis, IR and UV spectroscopy, X-ray phase analysis and X-ray diffraction analysis. Tests of the water-soluble complex with 2-aminoethanol ZnHL3− · 3(H3NCH2CH2OH)+ · 2H2O in the laboratory experiment with seeds of two agricultural crops showed a positive agronomic effect.

This study is to research the phylogeography of Phaneroptera falcata (Poda, 1761) in the Volga river basin based on the mtDNA Cytochrome C Oxidase subunit 1 (COI) gene fragment at the last Pleistocene glaciation episode. The studied location is the Volga river basin, a territory within the central and partially southern parts of European Russia; it includes the rivers Volga, Oka, Khoper and Don basins. We used the traditional molecular phylogeography methods: mtDNA COI gene fragment from the key locations within the studied area was sequenced and then analyzed (cladogram topology, haplotype diversity, cladogram calibration etc.). The phylogenetic tree shows the dispersion of our samples over the following regions: Lower Volga, Middle Volga, Lower Oka, Middle Oka, Upper Oka, Don basin, Khoper basin. Nine haplotypes determined from our samples; they are grouped into 7 haplogroups. Six of them are in the basins of the main rivers of the Volga region: three haplogroups - on the Oka (Upper, Middle and Lower Oka respectively), haplogroups of the Khoper and Don basins, and the haplogroup of the Middle Volga combining two subgroups – Lower and Middle Volga basins. The distribution of found haplogroups correlates with big river basins in the Volga area (Volga, Oka, Khoper, Don).

A highly efficient PASE approach to a new class of polycyclic purine derivatives has been proposed. The strategy includes a consecutive reduction, auto-aromatization, and heterocyclization of the initial nitrobenzimidazopyrimidines obtained by a three-component condensation. It was shown that reduction of nitrobenzimidazopyrimidines by metals in acidic media was more efficient than heterogeneous hydro­genation. Novel derivatives of benz[4,5]imidazo[1,2-a]purines were obtained­ in good yields and the proposed structure was confirmed by X-ray crystal structure analysis. The obtained convergent benzimidazopurines combine two relevant medicinal chemistry scaffolds – benz­imidazole and purine.

Cascade reaction of 2 equiv. of furfural (or equimolar amounts of furfural and aromatic aldehyde) with secondary amines and ethyl cyanoacetate afforded diethyl esters of 8-(dialkylamino)-3-aryl-6-oxo-2,4-dicyanobicyclo[3.2.1]octane-2,4-dicarboxylic acids with yields of 37–54%. Antimicrobial activity of a number of obtained compounds in vitro was studied, and biological activity in silico was analyzed. The obtained bicyclo[3.2.1]octanes are inactive or exhibit weak fungicidal activity, but exhibit moderate bactericidal effect.

Hydroxymethylation of (E)-3-aryl-2-cyanoprop-2-enethioamides with an aqueous alcoholic solution of formaldehyde has afforded (E)-3-aryl-N-(hydroxymethyl)-2-cyanoprop-2-enethioamides. The predictive analysis of the biological activity of the obtained compounds in silico has been carried out.

Direct asymmetric three-component Mannich reaction involving simple ketones (such as cyclohexanone, acetone, and acetophenone) as donors and catalyzing by silver tartaric acid-derived phosphate was realized to afford a series of optically active β-amino-ketone derivatives in high yields (up to 96%) and good-to-high enantioselectivities (up to 97%) with moderate-to-good diastereoselectivities. This is the first example of direct catalytic asymmetric three-component Mannich reaction via a chiral counteranion-directed strategy.

The new σ-alkynyl iron(II) complex Cp(CO)2Fe-C≡C-(2-C4H3S) was synthesized with application of several known approaches based on the transition metal (Pd/Cu–, Au–, Cu– and Pd–) catalyzed Fe–C coupling reactions of 2-ethynylthiophene or 2-[(trimethylsilyl)ethynyl]thiophene with cyclopentadienyliron dicarbonyl iodide. The yield of the complex in these reactions was found to strongly depend on the catalyst used. The conditions, catalysts, and reagents that provide the highest yields of the desired 2-thienylethynyl iron complex were determined. The complex was characterized by IR, 1H and 13C NMR spectroscopy. The molecular structure of Cp(CO)2Fe–C≡C-(2-C4H3S) established by X-ray diffraction analysis exhibits a three-leg piano stool geometry. The redox properties of the new complex were studied.

Introduction. At present, in science and technology, new computational problems constantly arise with large volumes of data, the solution of which requires the use of powerful supercomputers. Most of these problems come down to solving systems of linear algebraic equations (SLAE). The main problem of solving problems on a computer is to obtain reliable solutions with minimal computing resources. However, the problem that is solved on a computer always contains approximate data regarding the original task (due to errors in the initial data, errors when entering numerical data into the computer, etc.). Thus, the mathematical properties of a computer problem can differ significantly from the properties of the original problem. It is necessary to solve problems taking into account approximate data and analyze computer results. Despite the significant results of research in the field of linear algebra, work in the direction of overcoming the existing problems of computer solving problems with approximate data is further aggravated by the use of contemporary supercomputers, do not lose their significance and require further development. Today, the most high-performance supercomputers are parallel ones with graphic processors. The architectural and technological features of these computers make it possible to significantly increase the efficiency of solving problems of large volumes at relatively low energy costs. The purpose of the article is to develop new parallel algorithms for solving systems of linear algebraic equations with approximate data on supercomputers with graphic processors that implement the automatic adjustment of the algorithms to the effective computer architecture and the mathematical properties of the problem, identified in the computer, as well with estimates of the reliability of the results. Results. A methodology for creating parallel algorithms for supercomputers with graphic processors that implement the study of the mathematical properties of linear systems with approximate data and the algorithms with the analysis of the reliability of the results are described. The results of computational experiments on the SKIT-4 supercomputer are presented. Conclusions. Parallel algorithms have been created for investigating and solving linear systems with approximate data on supercomputers with graphic processors. Numerical experiments with the new algorithms showed a significant acceleration of calculations with a guarantee of the reliability of the results. Keywords: systems of linear algebraic equations, hybrid algorithm, approximate data, reliability of the results, GPU computers.

A series of derivatives of 5-hydroxyalkylamino-1,3-oxazoles were synthesized. Among these derivatives, 5 compounds have been evaluated for their activities against a normal laboratory human cytomegalovirus (HCMV) strain, AD169, in human foreskin fibroblast (HFF) cells. Bioassays showed that among these, 2 compounds containing a remainder of glucamine exhibited moderate antiviral activity (compounds 9 and 15, EC50 = 5.42 µM, CC50 > 150 µM, SI50 > 28 and EC50 = 4.91 µM, CC50 > 150 µM, SI50 > 31, respectively). The difference between these compounds is that the first contains a phtalimide radical at position 4 and phosphoryl at position 5, whereas the latter contains a phenyl radical and a cyano group in the corresponding positions. However, they were considerably less active than the control drug, ganciclovir (EC50 = 0.32 µM, CC50 > 150 µM and SI50 > 476), in this assay. These and previously obtained data allow us to consider 1,3-oxazole as a promising backbone for the synthesis of new compounds with anti-HCMV activity.

The high energy footprint of commodity gas purification and increasing demand for gases require new approaches to gas separation. Kinetic separation of gas mixtures through molecular sieving can enable separation by molecular size or shape exclusion. Physisorbents must exhibit the right pore diameter to enable separation, but the 0.3-0.4 nm range relevant to small gas molecules is hard to control. Herein, dehydration of the ultramicroporous metal-organic framework Ca-trimesate, Ca(HBTC)⋅H2 O (H3 BTC=trimesic acid), bnn-1-Ca-H2 O, affords a narrow pore variant, Ca(HBTC), bnn-1-Ca. Whereas bnn-1-Ca-H2 O (pore diameter 0.34 nm) exhibits ultra-high CO2 /N2 , CO2 /CH4 , and C2 H2 /C2 H4 binary selectivity, bnn-1-Ca (pore diameter 0.31 nm) offers ideal selectivity for H2 /CO2 and H2 /N2 under cryogenic conditions. Ca-trimesate, the first physisorbent to exhibit H2 sieving under cryogenic conditions, could be a prototype for a general approach to exert precise control over pore diameter in physisorbents.

The article discusses characteristics, fundamental and applied tasks of the Siberian Radioheliograph that is developed at the ISTP SB RAS Radio Astrophysical Observatory and spectropolarimetric complex that measures the total flux of solar radio emission. The multi-wave mapping of the Sun in the microwave range is a powerful and relatively inexpensive, in comparison with space technologies, means of observing solar activity processes and diagnosing plasma parameters. All-weather monitoring of electromagnetic solar emission (in the range from meter to millimeter waves, including measurements of the solar activity index at 2.8 GHz), and at the location of other diverse diagnostic facilities of the Heliogeophysical Complex, is of particular value. Radioheliograph data is necessary to develop and implement methods of short-term forecast of solar flares, measurements of kinematics and characteristics of coronal mass ejection plasma, forecast of characteristics of fast solar wind streams.

Phytoplankton are extraordinarily diverse, comprising 13 phylogenetic groups, with diatoms, dinoflagellates, and haptophytes among the most prominent eukaryotes in the ocean. Development of sensor technologies for rapid taxonomic and physiological analysis of phytoplankton communities is crucial for ecological monitoring programs in the global ocean. We describe a novel, ultra-sensitive, multi-spectral fluorescence induction and relaxation instrument (a mini-FIRe) and examine its analytical capability of rapidly determining phytoplankton taxonomic groups, as well as physiological characteristics and photosynthetic rates. We collected and analyzed the database of spectral and photosynthetic properties of major taxonomic groups of phytoplankton. We revealed that the spectral shape of the functional absorption cross-section of Photosystem II (PSII), sPSII(lex), is remarkably constrained within each major phylogenetic group of eukaryotic phytoplankton, including diatoms, haptophytes, dinoflagellates, and chlorophytes. Variability in sPSII(lex) within each group was significantly smaller than the difference between groups. We also examined the classical excitation spectra of chl a fluorescence yields, Fm(lex). Our comparative analysis revealed that sPSII(lex) is a better and more specific proxy for taxonomic analysis. For instance, our developed sPSII-based algorithm correctly identified 90% of experimental data, compared to 77% identified by the Fm-based algorithm. Our results suggest that the multi-color variable fluorescence analysis offers a tool for combined physiological and taxonomic analysis, including identification of major phyla within the ‘red’ lineage of eukaryotic phytoplankton.

The reaction of N-substituted amides of 3-amino-4,6-diarylthieno[2,3-b]pyridine-2-carboxylic acids with ninhydrin in the presence of catalytic amounts of sulfuric acid gave 1′-spiro[indene-2,2′-pyrido[3′,2′:4,5]thieno[3,2-d]pyrimidine]-1,3,4′(3′H)-triones. Structure of a number of key compounds was studied using 2D NMR spectroscopy; the bioavailability parameters of the obtained compounds in silico were calculated. In a laboratory experiment, a moderate antidote effect was revealed with respect to the 2,4-D herbicide for one compound.

A series of 3,3-bis(indol-3-yl)-1,3-dihydroindol-2-ones containing substituents at different positions of the oxindole ring were synthesized to study the effect of the position of the substituent on biological activity. Some of the new derivatives showed high in vitro cytotoxic activity (MTT assay) on human tumor cell lines and lower (60 and 150 times less) cytotoxicity on donor human fibroblasts compared to doxorubicin.

A method is proposed for processing large data sets of fluorescence decay kinetic curves using data mining algorithms to determine the parameters of biophysical and optical processes in molecular systems. The idea of this method involves breaking the initial set of fluorescence decay curves into clusters in terms of some degree of similarity, finding medoids of the clusters, applying a dimensionality reduction method to the data and imaging the experimental data in two- and three-dimensional space, and analyzing the decay curves of the medoids using analytic or simulation models. The applicability of the method is examined for the example of analyzing sets of data representing systems of fluorophores. This method requires substantially less time and calculations of the analytic approximation functions, while the accuracy of the estimated parameters is higher than in the classical approach.

Innovative technology of HDTV-borating, that is distinguished by high hardness, strength, wear resistance and corrosion resistance occupies a special place among the hardening processes for steels and construction materials. During the new technology process HDTV-boration of structural steel 65Mn (65Г in Russian) under a mix layer of charge mixture based on fused borate fluxing agent P-0.66, boron carbide and intermetallic compounds FexAly, NixAly.Using the methods of X-ray phase analysis, spectrography and metallography, the composition and structure of coatings were determined, the microhardness distribution over the coating thickness was studied. In the coatings, new phases of intermetallic compounds, the double superhard boride Fe2AlB2, were found; in the coatings, the base iron boride is FeB, what leads to an increase in their hardness and wear resistance. Modification of boride coatings formed by intermetallic compounds with melting temperatures close to the process temperature of HFC surfacing leads to a decrease in the cracks number and the appearance of new consumer qualities of the material.

The preferences of the end members of the lanthanide series (Er3+, Tm3+, Yb3+ and Lu3+) for Bi and Fe sites in BiFeO3 were investigated in this paper using X-ray powder diffraction. It was shown that: (1) the crystal structure of the BiFeO3-derived solid solutions remains rhombohedral in the Ln3+ concentration range from 0.01 to 0.1; (2) for the Er3+-, Tm3+- and Yb3+-doped materials, the unit cell parameters of solid solutions (Bi1-xLnxFeO3 or BiFe1-xLnxO3, x = 0–0.1) decrease with increasing x regardless of the selected stoichiometry; (3) for the materials with the same x, the unit cell parameters increase across the Er3+ - Tm3+ - Yb3+ series despite the decrease in ionic radius that occurs across the lanthanide series; and (4) for the Lu3+-doped materials, the unit cell parameters show only a minor increase. These results suggest that with the decreasing ionic radius of the lanthanides, simultaneous doping on the A and B sites corresponding to the formula Bi1-x+zLnх-zFe1-zLnzO3 (Tm3+, Yb3+) gradually replaces dominant A-site doping (Er3+) and eventually finishes with B-site doping (Lu3+). Variations in the magnetic properties of the doped samples indirectly confirm systematic changes in the preferences of the end members of the lanthanide series for Fe sites in BiFeO3: the values of Ms and Mr decrease drastically with the decreasing size of the Ln3+ cation to the extent that the hysteresis loops for the Lu3+-containing samples have a narrow and lenticular shape, which may be due to the dilution of the Fe-sublattice by Lu3+ cations. The samples show a piezoelectric coefficient d33 of 15 pC/N on average and up to 30 pC/N in individual specimens. Despite belonging to a class of multiferroics, Ln3+-containing solid solutions of BiFeO3 show no magnetoelectric or magnetodielectric response due to the weak coupling between piezoelectric and magnetic subsystems.

A method for studying stamukhas using the modern field equipment is considered. The peculiarities of morphometric characteristics and parameters of the internal structure of stamukhas are analyzed. The interrelation between the consolidated layer thickness and the accumulated freezing degree days is derived for different seas. The comparative analysis of morphometric characteristics and the consolidated layer in the ice-covered seas of Russia is carried out. It is shown that the formation of stamukhas in different regions has specific features depending on the depth, bottom topography, drift characteristics, ice thickness, and dates of fast ice formation. The maximum thickness of the consolidated layer is registered in the Kara and Laptev seas.

An optical vortex passed through an arbitrary aperture (with the vortex center found within the aperture) or shifted from the optical axis of an arbitrary axisymmetric carrier beam is shown to conserve the integer topological charge (TC). If the beam contains a finite number of off-axis optical vortices with different TCs of the same sign, the resulting TC of the beam is shown to be equal to the sum of all constituent TCs. For a coaxial superposition of a finite number of the Laguerre-Gaussian modes (n, 0), the resulting TC equals that of the mode with the highest TC (including sign). If the highest positive and negative TCs of the constituent modes are equal in magnitude, then TC of the superposition is equal to that of the mode with the larger (in absolute value) weight coefficient. If both weight coefficients are the same, the resulting TC equals zero. For a coaxial superposition of two different-amplitude Gaussian vortices, the resulting TC equals that of the constituent vortex with the larger absolute value of the weight coefficient amplitude, irrespective of the relation between the individual TCs.

Chemical feedback loops in fluids can produce not only chemical oscillations, but also density variations that generate solutal buoyancy forces, which in turn initiate fluid flow. Using analytical and computational models, we herein examine how the reaction-induced flows alter the chemical oscillations in a fluid-filled chamber whose top and bottom walls are coated with different enzymes. Due to this chemo-fluidic coupling, the systems form oscillating flow patterns, which combine the characteristic size of the buoyancy-driven convection rolls with the frequency of the chemical oscillations. With changes in the distance between the enzyme-coated walls, the convective flows not only enhance or suppress the chemical oscillations, but also substantially increase the amplitude and frequency of the oscillations and extend the regime of the oscillatory behavior. These design principles can facilitate the development of artificial biochemical networks that act as chemical clocks. Oscillating chemical reactions are ubiquitous in living systems. Here, the authors propose a mathematical model to study how chemically-driven density gradients produced by enzymatic reactions can trigger hydrodynamic instabilities coupling with chemical oscillations.

Terminal polychlorides of hyperbranched polyester polyol Boltorn H20 were synthesized. Subsequent treatment of the resultant polychlorides with absolute pyridine or triphenylphosphine led to the formation of products of varying degrees of functionalization, containing pyridinium or triphenylphosphonium moieties in terminal positions.