Current State of Pasture Vegetation of the Arid Zone (On the Example of Key Rural Municipalities of the Republic of Kalmykia)

The article presents the results of field observations over 2012–2018 carried out by the Department of Environmental Research of the Institute for Complex Studies of Arid Territories. The work includes materials on the climatic review and the original results of geobotanical investigation of 5 farms in rural municipalities of the Republic of Kalmykia (RK) over the period of the study. We used materials of a large geobotanical survey of YUZHNIIGIPROZEM Company (1991–1995) and materials of earth remote sensing (by Landsat satellite). According to the studies, the period from 2012 to 2018 demonstrates a general trend of climate warming throughout the territory of Kalmykia accompanied by a decrease in precipitation and an increase in extreme droughts in the summer. Geoecological monitoring of pastures at five key sites of the RK revealed that in the dry steppe zone (Manych municipality) and in the semi-desert zone (Khanatinsky municipality), deterioration of pastures is observed; in the desert zone (Adykovskoye municipality), significant degradation processes were identified associated with strong anthropogenic impact and fires, manifested in the loss of valuable food crops (wormwood) and increased influence of cereal crops. Floristic and phytocenotic analyzes revealed an increase in the number of plant species in the weed and ruderal groups

T35 Epigenetic changes in human cervical carcinomas associated with viral induced pathogenesis

Epigenetics investigates mechanisms that control inheritance of gene expression program during somatic cell divisions. These mechanisms include regulation by DNA methylation, histone post-translational modifications and nucleosome positioning, functioning of regulatory non-coding RNAs, control of alternative splicing of mRNA precursors and high-order chromatin organization. Genome-wide loss of epigenetic stability and increased epigenetic plasticity are common features of all tumor types. In normal tissues epigenetic plasticity allow cells to response on environment signals. Thus, in tumor cells its constitutive activation leads to epigenetic heterogeneity that are the additional hallmark of the most of the classical cancers. Cervical cancers are one of the most interesting models for the analysis of the role of epigenetic changes in tumor progression. These types of tumors are associated with infection of human papilloma viruses of so-called high-risk group (HR-HPV) and characterized by well-defined stages of malignant conversion from intraepithelial neoplasias to carcinomas. The viral DNA can persist in episomal form or integrates into the host-cell genome.Cellular genomes encode genetic information in their linear sequence, but appropriate gene expression requires chromosomes to fold into dynamic complex three-dimensional structures. Scaffold/matrix attachment regions (S/MARs) are specialized genomic DNA sequences that take part in organization of these structures. We demonstrated that methylation of S/MARs was required for their attachment to nuclear matrix and that methylation status of S/MARs was changed in cervical cancer cell compared to normal cells.DNA methylation plays an important role in the regulation of gene expression. We found that methylation of the regulatory sequences in the HPV16 genome specifically changes in transformed compared to the normal cervical epithelial cells. Next, we showed that methylation of the transcription factor binding sites modulates the viral oncogene expression. These data suggest that the HPV16 genome methylation may represent an important mechanism that initiates the development of HPV-associated tumors.Using next generation sequencing, we identified pattern of differentially expressed microRNAs in clinical samples of the cervical lesions. We confirmed expression of microRNAs that have been described previously as well as identified new microRNAs that can be potentially involved in the development and progression of cervical cancer. Spectrum of differentially expressed microRNAs includes microRNAs targeting tumor-suppressor genes as well as oncogenes.Telomerase is a key regulator of cell proliferation. This enzyme is silent in normal cells and activated in most of the tumors. Few forms of RNA (hTERT), encoded by telomerase gene were detected in different tumor cells and among them three forms (alfa, beta and gamma) are most well pronounced. We found that in cervical tumors expression of all three forms are significantly increased. In some cases, we also observe higher level of hTERT expression in neighboring “normal tissue”. The correlation between expression levels of these three forms varied on different stages of the disease (three stages on intraepithelial neoplasias and carcinomas). The function of these three hTERT forms is still not well understood

Optical Properties of Cu2S/SnS2 Precursor Layers for the Preparation of Kesterite Cu2SnS3 Photovoltaic Absorber

The Cu2S and SnS2 layers have been prepared by the chemical bath deposition method. The results of SEM and EDX analyses confirm a high stoichiometry of the synthesized semiconductor thin films. The optical properties of the Cu2S and SnS2 layers have been studied, and the optical band gap values have been determined. Keywords: thin films, sulfides, band gap, hydrochemical deposition, transmittance, photovoltaic absorbe

Stripping-voltammetric determination of transition metals using electrodes modified by azacrown compounds

Voltammetric properties of macrocyclic complexes of transition metals are studied by using a carbon-paste electrode modified by diaza-18-crown-6, Cyclam, and their derivatives. A selective stripping-voltammetric procedure is proposed for determining Ni(II) and Co(II) with a carbon-paste electrode modified by Cyclam and its derivatives. To improve the sensitivity and selectivity of analysis, it is suggested that metal ions be preconcentrated at the surface of the modified electrode by using a 0.1 M NaCl solution as a supporting electrolyte with the following recording of voltammograms in the range from -0.3 to 0.8 V in a 0.1 M KOH solution. The detection limits for Ni(II) and Co(II) are 4 × 10-8 and 1.2 × 10-7 M, respectively. © 1996 MAEe Cyrillic signK Hayκa/Interperiodica Publishing

Extraction of inorganic and organic substances from aqueous solutions as host-guest complexes by vaseline oil containing crown compounds

Extraction of some metal ions and biologically active organic compounds as host-guest complexes from aqueous phase by solutions of crown compounds in Vaseline oil was studied. The same extraction systems were studied using the extractant as a constituent of a carbon paste electrode. The conditions ensuring the maximum extraction capability of Vaseline oil in the presence and absence of crown compound were found. © 1996 MAEe cyrillic signK Hayκa/Interperiodica Publishing

Stripping-voltammetric determination of transition metals using electrodes modified by azacrown compounds

Voltammetric properties of macrocyclic complexes of transition metals are studied by using a carbon-paste electrode modified by diaza-18-crown-6, Cyclam, and their derivatives. A selective stripping-voltammetric procedure is proposed for determining Ni(II) and Co(II) with a carbon-paste electrode modified by Cyclam and its derivatives. To improve the sensitivity and selectivity of analysis, it is suggested that metal ions be preconcentrated at the surface of the modified electrode by using a 0.1 M NaCl solution as a supporting electrolyte with the following recording of voltammograms in the range from -0.3 to 0.8 V in a 0.1 M KOH solution. The detection limits for Ni(II) and Co(II) are 4 × 10-8 and 1.2 × 10-7 M, respectively. © 1996 MAEe Cyrillic signK Hayκa/Interperiodica Publishing

Electrochemical Oxidation of Azacrown Transition Metal Complexes on a Graphite Electrode

Azacrown compounds and their 3d-transition metal complexes undergo oxidation on a graphite electrode in aqueous and organic solutions. The macrocyclic ligands are oxidized to radical cations which are involved in further electrode reactions. The one-electron oxidation of diazabenzo-18-crown-6 and triazabenzo-18-crown-6 is reversible. Diaza-18-crown-6, as well as cyclam and its derivatives are oxidized irreversibly and at more positive potentials. The central atom in the species resulting from the oxidation of the Co(II), Ni(II), and Cu(II) complexes has the oxidation state 3+. The voltammetric characteristics of the oxidation of the macrocyclic complexes are solvent-dependent

Stripping-voltammetric determination of some amino acids on a carbon-paste electrode modified by crown ethers

A method for detecting sulfur-containing amino acids on a carbon-paste electrode modified by dibenzo-18-crown-6 or dibromodibenzo-18-crown-6 ethers is developed. The selectivity of the method is accounted for by a specific interaction between crown ethers (modifying agents) and protonated amino groups of organic molecules of the analyte adsorbed by the surface of the modified electrode as a host-guest complex. The determination limits (clim) of cysteine, homocysteine, and glutathione are equal to (2-5) x 10-8 M. © 1997 MAEe Cyrillic signK Hayκa/Interperiodica Publishing

Stripping voltammetry of biologically active organic compounds as host-guest complexes at electrodes modified with crown ether

Procedures for determining the biologically active organic compounds Ioxynil, Prefix, Sayfos, Cythioate, and Karbation by stripping voltammetry using carbon-paste electrodes modified with dibenzo-18-crown-6 (DB18C6) or dibromo-DB18C6 crown ether were developed. The selectivity and sensitivity were improved by using a preconcentration of organic molecules as host-guest complexes at the electrode. The pesticide content was monitored by the oxidation peaks of Karbation and Ioxynil and by the peak current corresponding to the formation of mercury mercaptide for the S-containing compounds. The determination limits of the procedures suggested are 4.0 × 10-9,4.6 × 10-7, 3.8 × 10-8, 8.0 × 10-8, and 9.0 × 10-8 M for the pesticides Karbation, Prefix, Ioxynil, Sayfos, and Cythioate, respectively. © 1998 MAEe Cyrillic signK Hayκa/Interperiodica Publishing

Development of “green” and organic production in dairy cattle breeding

The problem of creating environmentally friendly products has become particularly relevant during the COVID-19 pandemic from the standpoint of ensuring the health of the nation as well as from the point of view of increasing the competitiveness and efficiency of agricultural enterprises. Special attention should be paid to the issues of regulation and justification of the principles of building “green” and organic production that currently remain unsolved. The purpose of this study is to justify the priority of technological development in the agricultural sector of the economy by comparing development trends in the global and domestic market of organic products considering the analysis of the formation of the legislative framework in this area of activity as well as identifying industry principles of the typical for dairy cattle breeding production. The methods of analysis, synthesis, comparison, and generalization were used in the article. The results of the study can serve as a basis for the sustainable development of “green” and organic production, both in dairy cattle breeding and other sectors of agriculture as well as basis for the development of federal and regional programs for the organic market growth in the Russian Federation