Diagnostics of laser-induced plasma on carbon-based polymer material using atomic and molecular emission spectra

Time-integrated optical emission analysis of laser-induced plasma on Teflon is presented.Plasma was induced under atmospheric pressure air using transversely excited atmospheric CO_(2) laser pulses.Teflon is a C-based polymer that is,among other things,interesting as a substrate for laser-induced breakdown spectroscopy analysis of liquid samples.This study aimed to determine the optimal experimental conditions for obtaining neutral and ionized C spectral lines and C2 and CN molecular band emission suitable for spectrochemical purposes.Evaluation of plasma parameters was done using several spectroscopic techniques.Stark profiles of appropriate C ionic lines were used to determine electron number density.The ratio of the integral intensity of ionic-to-atomic C spectral lines was used to determine the ionization temperature.A spectral emission of C2 Swan and CN violet bands system was used to determine the temperature of the colder,peripheral parts of plasma.We critically analyzed the use of molecular emission bands as a tool for plasma diagnostics and suggested methods for possible improvements.

Chemical composition of natural waters at Broknes Peninsula, Larsemann Hills, Antarctica

The article contributes to the study of the content of major and trace elements in various types of natural waters of the Broknes Peninsula,Larsemann Hills,Antarctica collected in January–February 2014 and 2020 during the 7th and 12th Belarusian Antarctic Expeditions.Samples of old(13 samples)and newly fallen snow(5),lakes(23)and groundwater(8)were analyzed.The content of 25 major and trace elements was determined using ICP-MS method,main anions was determined by titrimetric and turbidimetric methods.Good similarity chemical composition of snow,groundwater and lake waters in spite of differences in the content of major ions and trace elements has been obtained.The influence of marine salts on natural waters are analyzed,and their accumulation in lake waters especially in the endorheic small and shallow lakes in spite of ultra-oligotrophic atmospheric precipitates are shown.The spatial heterogeneity of groundwater and temporal and spatial heterogeneity of lake waters have been demonstrated.The results are important for understanding the variabilities of major and trace elements content in snow,groundwater and lake waters,and their relationship,as well as for identifying trends in their change,taking into account anthropogenic loads in the region and climate change.

DFT Investigations(Geometry Optimization, UV/Vis, FT-IR, NMR, HOMO-LUMO, FMO, MEP, NBO, Excited States) and the Syntheses of New Pyrimidine Dyes

In the present work, the molecular structures of two new synthesized dyes：（4,6-dimethylpyrimidin-2-ylamino）（5-p-tolylisoxazol-3-yl）methanol（PS-1） and N-（4,6-dimethylpyrimidin-2-yl）-5-phenylisoxazole-3-carboxamide（PS-2）, have been investigated using density functional theory（DFT） in dimethylformamide（DMF） for the first time. The electronic spectra of new dyes in a DMF solvent were carried out by time dependent density functional theory（TD-DFT） method. After quantum-chemical calculations two new dyes for the optoelectronic applications were synthesized. FT-IR spectra of the title compounds are recorded and discussed. NucleusIndependent Chemical Shifts（NICS） calculations have also been carried out for the title compounds. The computed absorption spectral data of the title compounds are in good agreement with the experimental data, thus allowing an assignment of the UV spectra. The HOMO and LUMO molecular orbitals, excitation energies and oscillator strengths for the dyes have also been calculated and presented.

An assessment of the impacts of diesel power plants on air quality in Antarctica

This study assessed the effects of diesel generators on air quality in the Antarctic.These devices are the primary energy sources for Antarctic research stations and the main stationary sources of anthropogenic emissions in this region.Taking the Vecherny Oasis,Enderby Land,East Antarctica as an example,NOx,SO2 and PM10 emissions were estimated and surface concentrations of these same pollutants as well as the dry deposition of PM10 were calculated for various periods of exploration of the oasis,based on generator capacities.Estimated values were compared with air quality standards and background air concentrations.The areas associated with increased maximum hourly surface concentrations of SO2,NO2 and PM10 over the past 30 a were found to have been reduced by factors of 4355,916 and 1327,respectively.The region affected by increased maximum monthly PM10 deposition has been reduced by a factor of 7.Emissions,surface concentrations and dry depositions in the Vecherny Oasis were calculated for diesel generators in the same power range as used at Antarctic research stations.The most powerful diesel generator currently scheduled to be installed in this region was predicted to generate maximum hourly NO2 concentrations above 50μg m^- 3,which is 13 times greater than current levels.The area over which the PM10 deposition rate will exceed 10 mg m^- 2 month 1 will be increased by a factor of 40.The technique employed herein has been demonstrated to be applicable to the preliminary assessment of stationary sources of pollutant emissions in Antarctica,including retrospective assessments.

Antitumor and Antioxidant Activities of the New Anthraquinone Derivatives: Synthesis, DPPH, ABTS, Biological and DFT Investigations

In the given research,for the first time the molecular structures of four new anthraquinone derivatives have been predicted and investigated by using Density Functional Theory(DFT/M052X/MidiX)in water.After quantum-chemical calculations the title compounds have been synthesized.The M052X/MidiX method has been employed to obtain Bond Dissociation Enthalpy(BDE),Mulliken Charges,NBO analysis,Ionization Potential(IP),Electron Affinities(EA),HOMO and LUMO energies,Hardness(η),Softness(S),Electronegativity(μ),Electrophilic Index(ω),Electron Donating Power(ω^-),Electron Accepting Power(ω^+)and Energy Gap(Eg) in order to infer scavenging activity of the four new synthesized anthraquinone derivatives(Sm-3,Sm-4,Sm-7,Sm-10).Comparative analysis of BDE of Sm-3,4,7,10 indicates the weal antioxidant potential of these structures.These molecules have high antioxidant potential due to the planarity and formation of intramolecular hydrogen bonds.Experimental investigations establish high antioxidant and antitumor activities of the synthesized anthraquinone derivatives.

Genetic diversity and differentiation of pedunculate ( Quercus robur ) and sessile ( Q. petraea ) oaks

This study was conducted to determine the parent-off spring genetic structure of the pedunculate oak(Quercus robur L.),sessile oak(Q.petraea[Matt.]Liebl.)and their hybrids.Forty half-sib Quercus families and their maternal trees originating from one tree stand in southern Lithuania were analyzed using SSR and RAPD markers.Based on a preliminary study of leaf morphological traits,the individuals separated into six groups.The studied halfsib oak families were also compared for allelic diversity,including group variations;genotypic structure;genetic diversity;and the degree of genetic subdivision and diff erentiation.The level of genetic variation and subdivision was lower in the hybrid families than in the families of the parental species.Genotypic analysis of the half-sibling off spring showed the asymmetric nature of interspecifi c hybridization processes of pedunculate and sessile oaks in mixed stands.

DFT Study of Physisorption Effect of the Curcumin on CNT(8,0-6) Nanotube for Biological Applications

In the given work the adsorption properties of molecule curcumin((1 E,6 E)-1,7-bis(4-hydroxy-3-methoxyphenyl)-1,6-heptadiene-3,5-dione) on CNT(8,0-6) nanotube were investigated by the density functional theory(DFT) in the solvent water for the first time. The non-bonded interaction effects of compounds curcumin and CNT(8,0-6) nanotube on the electronic properties, UV/Vis spectra, chemical shift tensors and natural charges were determined and discussed. The electronic spectra of the compound curcumin and the complex CNT(8,0-6)/curcumin in the solvent water were calculated by time dependent density functional theory(TD-DFT) for investigation of the maximum wavelength value of molecule Curcumin before and after the non-bonded interaction with the CNT(8,0-6) nanotube and molecular orbitals involved in the formation of absorption spectrum of the complex CNT(8,0-6)/curcumin at maximum wavelength.

Prognostic Significance of Comparison of Clinical Indicators with Manifestations of Genetic Polymorphism of Glutathione-S-Transferases in Non-Small Cell Lung Cancer

The article presented the results of comparison of polymorphic variants of the genes GSTM1, GSTT1, GSTP1 and clinical manifestations of non-small cell lung carcinoma. The association of the genotype GSTT1 (del) with the risk of developing squamous cell lung cancer has been revealed (OR = 2.54 CI: 1.13 - 5.72, p = 0.035). Analysis of patient survival rate (n = 173) in groups of various histological types of lung cancer showed that in the group of squamous cell lung cancer (n = 91) in patients with genotype GSTT1 (del), the survival rate median was significantly higher—84 months (95% CI 12.4 - 155.7) than in patients with the genotype GSTT1 (+)—36 months (95% CI 25.2 - 46.8, p = 0.045). In contrast, in the adenocarcinoma group (n = 82), the survival rate median in patients with the genotype GSTT1 (del) was 19 months. (95% CI 6.2 - 33.5), and in patients with genotype GSTT1 (+)—67 months (95% CI 50.1 - 84.0), which is the basis for continuing this comparison in an additional group of testees, as the sampling did not achieve the reliability of p = 0.12. Hypothetically, these differences may be due to differences in the gender composition of squamous cell lung cancer and adenocarcinoma and the involvement of GST enzymes in the metabolism of estrogens in adenocarcinoma in women and other hormonal background and reactivity of the male body with squamous cell carcinoma. Further research and subsequent analysis of the results will be aimed at confirming this hypothesis.

Optimization, Spectroscopic(FT-IR, Excited States, UV/Vis) Studies, FMO, ELF, LOL, QTAIM and NBO Analyses and Electronic Properties of Two New Pyrimidine Derivatives

In the given research,the molecular structures of two new compounds,4-((E)-3-(dimethylamino)styryl)-6-((E)-4-(dimethylamino)styryl)pyrimidine-2-amine(PM-1)and N-(4-((E)-3-(dimethylamino)styryl)-6-((E)-4-(dimethylamino)styryl)pyrimidine-2-yl)-4,6-dichloro 1,3,5-1,3,5-triazin-2-amine(PM-2),have been studied with the use of density functional theory(DFT/B3LYP/MidiX)in dimethylformamide(DMF)for the first time.The electronic spectra of the new compounds in a DMF solvent were carried out by temporally dependent density functional theory(TD-DFT)method.The computed absorption spectral data of the title compounds are in good agreement with the experimental data,thus allowing an assignment of the UV/Vis spectra.The equilibrium geometry,the HOMO and LUMO molecular orbitals,excitation energies,oscillator strengths and Natural Bond Orbital(NBO)analysis for the molecules have also been calculated and presented.FT-IR spectra of the title molecules are recorded and discussed.The electron location function(ELF),localized orbital locator(LOL)and quantum theory of atoms in molecules(QTAIM)analyses were also carried out.On the basis of polyvinyl alcohol(PVA)and synthesized molecules,polarizer for UV/Vis region of the spectrum has been developed.

Regularities of Nanofocusing of the Electromagnetic Field of a Fractal Rough Surface

A consistent physical and mathematical model of the propagation of electromagnetic waves in an inhomogeneous medium with strong discontinuities of the electromagnetic field at the interface of two media, which is a rough surface, was developed. Mathematical modeling of rough surfaces and their profiles was carried out using fractal geometry, which allows us to display the topology of the object as close as possible to reality. For real heterogeneous rough structures, we have developed a through-counting method that takes into account the continuity of the total current at the interfaces of adjacent media, the effect of induced surface charge and surface current. This approach lets one avoid the necessity to set surface impedances depending on the structure of the field being determined and on the material properties.

Theoretical Study of Interaction between Apalutamide Anticancer Drug and Thymine by DFT Method

The main purpose of this study is a better comprehension of the non-bonded interaction between an anticancer drug apalutamide and deoxyribonucleic acid(DNA).In the prese nt work,the in teraction between an ticancer drug apalutamide and one of the DNA bases called 2,-deoxythymidine 5,-monophosphate(thymine)by Density Functional Theory(DFT)calculations in the solvent water has been investigated for the first time.The non-bonded interaction effects of the molecule apalutamide with thymine on the electronic properties,chemical shift tensors and natural charges have been also detected.The natural bond orbital(NBO)analysis was performed for determining the role of electron donor and acceptor of the molecules apalutamide and thymine at the complex thymine/apalutamide.Both Electron location function(ELF),localized orbital locator(LOL)and quantum theory of atoms in molecules(QTAIM)analysis were carried out in order to determine the chemical bond nature in the investigated compounds.The values of ELF and LOL parameters for the selected bonds are small,which confirms the non-covalent character of these bonds in nature.The electronic spectra of the apalutamide drug,thymine and complex thymine/apalutamide in solvent water were calculated by Time Dependent Density Functional Theory(TD-DFT)for the investigation of interaction effect;Non-bonded interaction between the compound apalutamide and thymine has changed the value of λmax.

Effects of temperature and resource abundance on small- and large-bodied cladocerans: Community stability and species replacement

Understanding when small- or large-bodied cladocerans dominate zooplankton communities has received considerable debate over the past 50 years. While a large body of research has proposed that large-bodied species are superior competitors over small-bodied species, other studies have shown that small-bodied species can dominate at least under some environmental conditions. We tested the hypothesis that dominance by small- and large-bodied cladocerans varied in response to the coupled effects of food supply and temperature. Laboratory experiments with poly- and monocultures of small- and large-bodied cladocerans were performed at three temperatures (16°C, 22°C and 27°C) and with varying amounts of food supply. The results of the experiments showed that the small-bodied species (Ceriodaphnia quadrangula) dominated at low food supply and higher temperature, while the large-bodied species (Daphnia magna and Daphnia pulex) in contrast dominated at lower temperature and higher food supply. Furthermore, although there were variations in the relative biomass of the small- and large-bodied cladocerans in the polycultures, C. quandrangula replaced the two larger Daphnia species when they declined in biomass at low food supply. Species replacement in response to temperature and food supply helped to maintain the relatively constant level of total cladoceran biomass in the polycultures which was the most pronounced at the intermediate temperature. We suggest that the observed changes in dominance were similar to facilitative replacement rather than competitive exclusion. Physiological processes such as clearance rates can help to promote the succession of large- and small- bodied populations within a community along gradients of temperature and food availability.

Non-Monochromatic Electromagnetic Radiation of Inhomogeneous Media

A coordinated physicomathematical model for the propagation of a soliton-like electromagnetic pulse in a heterogeneous medium is developed in the presence of strong discontinuities in the electromagnetic field. The model is based on the reduction of Maxwell’s equations to the well-studied wave equation. When the electromagnetic pulse was specified, its amplitude modulation was taken into account, as was the nonstationary broadening of the spectral line. Conditions for matching the momentum for the first initial boundary-value problem are obtained. The time dispersion of the electrical induction is taken into account in terms of the function of signal conditioning which takes account of the broadening of its spectral line and integration over the continuous spectrum. With this approach, it is not necessary to neglect spatial derivatives, and also to use spatial nonlocal relations to take account of the effect of surface charge, surface current, and spatial dispersion of electrical induction at the interfaces of adjacent media.

Association of Polymorphic Variants of <i>VEGF</i>and <i>KDR</i>Genes with Development and Metastasing of Non-Small Cell Lung Cancer

Vascular endothelial growth factor (VEGF) is one of the most important and specific factors affecting angiogenesis in tumor development. VEGFR2 is a receptor encoded by the KDR gene. VEGF and VEGFR2 transmit a signal to intracellular tyrosine kinase cascades. Polymorphic variants of the VEGF and KDR genes significantly influence the expression levels of the endothelial growth factor and its receptor, which leads to a change in the activation of angiogenesis in oncopathological processes. In this study, the relationship between the polymorphic variants rs2010963, rs699947 and rs3025039 of the VEGF gene and rs1870377 and rs2071559 of the KDR gene was analyzed with the development of a specific histological type of non-small cell lung cancer and its clinical and morphological characteristics. It was established that the development of squamous cell carcinoma is associated with -634CC genotype of the VEGF gene and the genotypes containing -2578A allele of the VEGF gene reduce the likelihood of this cancer type development. The development of adenocarcinoma is associated with +936CC VEGF/1719TT KDR and +936CT VEGF/1719TT KDR combinations. In women with non-small cell lung cancer, -634GC genotype of the VEGF gene is associated with a greater degree of the primary lesion spread. Genotype -2578СС of the VEGF gene is associated with a higher degree of the primary tumor spread in the general group of patients and with regional metastases in women. Haplotypes -634G/-2578C/+936C are risky for the occurrence of metastases in regional lymph nodes in women.

Recent changes in breeding abundance and distribution of the Common Pochard(Aythya ferina)in its eastern range

Background:The Common Pochard(Aythya ferina)(hereafter Pochard),a widespread and common freshwater diving duck in the Palearctic,was reclassified in 2015 from Least Concern to Vulnerable IUCN status based on rapid declines throughout its range.Analysis of its status,distribution and the potential causes for the decline in Europe has been undertaken,but there has never been a review of its status in the major part of its breeding range across Russia to the Pacific coast.Methods:We reviewed the scientific literature and unpublished reports,and canvassed expert opinion throughout Russia to assess available knowledge about changes in the species distribution and abundance since the 1980s.Results:While accepting available information may not be representative throughout the entire eastern range of the species,the review found marked declines in Pochard breeding abundance in the last two decades throughout European Russia.Pochard have also declined throughout Siberia.Declines throughout the steppe region seemed related to local drought severity in recent years,necessitating further research to confirm this climate link at larger spatial scales.Declines in the forest and forest-steppe regions appeared related to the major abandonment of fish farms in western Russia that had formerly provided habitat for breeding Pochard.However,hyper-eutrophication of shallow eutrophic lakes,cessation of grazing and haymaking in floodplain systems necessary to maintain suitable nesting habitat and disappearance of colonies of the Black-headed Gull(Chroicocephalus ridibundus)in a number of wetlands were also implicated.Increasing invasive alien predator species(e.g.American Mink Neovison vison and Raccoon Dog Nyctereutes procyonoides)and increasing spring hunting were also thought to contribute to declines.Reports of expansion in numbers and range only came from small numbers occurring in the Russian Far East,including on the border with China and the long-established isolated population on Kamchatka Peninsula.Conclusions:Widespread declines throughout the eastern breeding range of the Pochard give continued cause for concern.Although we could address all the potential causal factors identified above by management interventions,we urgently need better information relating to key factors affecting site-specific Pochard breeding success and abundance,to be able to implement effective actions to restore the species to more favourable conservation status throughout its breeding range.

Study of impregnated cellulose thermal treatment process and properties of obtained active carbon

Single-stage process of obtaining active carbon by thermal processing of plant raw materials (mixture of different types of wood sawdust), impregnated with the mixture of phosphoric acid, urea and nitric acid salts has been developed. Active influence of impregnates on the process of carbonization and formation of carbon residue has been formed. It is established that carbon residue obtained in the interval of heating 20℃-(500℃-700℃), possesses high sorption activity to the vapors of organic compounds and has ion-exchange capacity. It has been showed that the value of carton residue depending on the impregnate used in the wood increases compared to the yield of non-treated initial raw materials by 3.1 times at 600℃ and by 4.2 times at 700℃.

Preparation and Characterization of Reduced Graphene-P3HT Composite Thin Films for Use as Transparent Conducting Electrodes

With the aim of producing simple and effective transparent conducting electrodes, the conducting polymer poly(3-hexylthiophene) (P3HT) incorporated with reduced graphene oxide film (rGO) (called rGO-P3HT) was prepared by spin-coating method. Structural, electrical and optical characterization showed that rGO-P3HT films 9.0 wt% P3HT exhibited good stability when exposed to the ambient atmosphere. These composite films of 200 nm thickness possess a sheet resistance and transparency of R□~ 17Ω and T ~ 72%, respectively. Owing to containing conducting polymer, rGO-P3HT-coated glass could be efficiently used in photovoltaic applications, in organic solar cells in particular, with the replacement of the indium tin oxide (ITO) and fluorine tin oxide (FTO) electrodes.

Pharmacokinetic Study and Toxicity of Leukovir: A New Combined Drug for the Treatment of Multiple Sclerosis

Leukovir, an enteric-coated tablet, is the original drug product for internal use. The well-known nucleosides cladribine and ribavirin are the active ingredients of the drug product leukovir. Pharmacokinetic parameters of the drug product for the internal use of leukovir active ingredients have been established. The cladribine half-absorption period was t1/2a = 49.5 h, C0 = 276.4 μg/ml, Cmax = 6.0 μg/ml. Distribution and accumulation parameters (Vd, Vss and AUC) have indicated that the drug distribution between the blood cells and blood plasma takes place in the same way, irrespective of the dosage form. Cladribine half-life period is t1/2e = 0.62 hours. The molecule total clearance and average lifetime in the body in the case of subcutaneous drug administration are approximately the same. Ribavirin is characterized by a half-absorption period of t1/2a = 0.71 h, C0 = 115.6 μg/ml and Cmax = 75.5 μg/ml. Ribavirin total volume of distribution (Vd = 1.3 l/kg) and stationary volume of distribution (Vss = 1.64 l/kg) were practically similar to leukovir when administered subcutaneously. The AUC value = 504.2 μg h/ml, which is 2.5 times less than that in the case of drug form administration. Leukovir was regarded as slightly toxic in an acute toxicity study. The risk of cumulation for this drug product is low.