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Polder A, Gabrielsen GW, Odland JØ, Savinova TN, Tkachev A, Løken KB, Skaare JU. Spatial and temporal changes of chlorinated pesticides, PCBs, dioxins (PCDDs/PCDFs) and brominated flame retardants in human breast milk from Northern Russia. THE SCIENCE OF THE TOTAL ENVIRONMENT 2008; 391:41-54. [PMID: 18063018 DOI: 10.1016/j.scitotenv.2007.10.045] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/06/2007] [Revised: 10/10/2007] [Accepted: 10/15/2007] [Indexed: 05/25/2023]
Abstract
This study presents for the first time temporal changes of organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs) in Russian human breast milk samples. Concentrations of OCPs and PCBs in samples from three locations in the North West of Russia in 2000-2002 (n=42), were compared to corresponding levels measured in 1993-1996 (n=58). In addition brominated flame retardants (BFRs), consisting of polybrominated diphenylethers (PBDEs) (including BDE-209) and hexabromocyclododecane (HBCD) were analysed in samples from 2000-2002 (n=37). The present levels of SigmaDDTs and SigmaHCHs were 5 and 10 times higher than corresponding levels in the neighbouring country Norway. Median concentrations of SigmaHCHs (196 microg/kg lw), SigmaCHBs (19.7 microg/kg lw) and SigmaPCBs(16) (316 microg/kg lw) were highest in Murmansk. The percentage of p,p'-DDT to SigmaDDTs and ratio DDE/DDT suggest possible ongoing use of DDT in Russia. Levels of PBDE were low and dominated by the congeners BDE-47 and BDE-153. The deca brominated BDE-209 was detected in all analysed samples (median concentration 0.19 microg/kg lipid). Levels of SigmaOCPs and SigmaPCBs decreased 56 and 30% in Murmansk and 36 and 43% in Arkhangelsk during the study period. The decline of SigmaOCPs was significant at both locations (p<0.05-p<0.0001). For SigmaPCBs, the decreasing trend was only significant in Arkhangelsk (p<0.0001). In addition, a decline of Sigmatotal TEQs (SigmaTEQs of PCDDs/PCDFs, non-ortho- and mono-ortho PCBs) was observed in Murmansk and Arkhangelsk during the study period. The exposure of infants by PCDDs/PCDFs and dioxin-like PCBs is still exceeding the daily tolerable intake (TDI) in North West Russia. However, the concentrations of PCDDs/PCDFs and dioxin-like PCBs seem to decline very rapidly.
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Smirnova EA, Gusev AA, Zaitseva ON, Lazareva EM, Onishchenko GE, Kuznetsova EV, Tkachev AG, Feofanov AV, Kirpichnikov MP. Multi-walled Carbon Nanotubes Penetrate into Plant Cells and Affect the Growth of Onobrychis arenaria Seedlings. Acta Naturae 2011. [DOI: 10.32607/20758251-2011-3-1-99-106] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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Polder A, Savinova TN, Tkachev A, Løken KB, Odland JO, Skaare JU. Levels and patterns of Persistent Organic Pollutants (POPS) in selected food items from Northwest Russia (1998-2002) and implications for dietary exposure. THE SCIENCE OF THE TOTAL ENVIRONMENT 2010; 408:5352-5361. [PMID: 20719362 DOI: 10.1016/j.scitotenv.2010.07.036] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/24/2010] [Revised: 07/07/2010] [Accepted: 07/14/2010] [Indexed: 05/29/2023]
Abstract
Residues of persistent organic pollutants (POPs) were analysed in 70 selected food items from Northwest Russia in 1998-2002. Levels of PCBs ranged from 0.2 to 16ng/g wet weight (ww) in dairy products and fats, 0.2 to 23ng/g ww in meat products, 0.5 to 16ng/g ww in eggs and 0.3 to 30ng/g ww in fish. High levels of DDT (16ng/g ww) were found in locally produced butter from Kola Peninsula, in pork fat from Arkhangels region (10 to 130ng/g ww) and in some fish samples from White Sea and Kargopol region (17 and 30ng/g ww). Findings of low DDE/DDT ratios in many of the studied food items indicated recent contamination to DDTs. Mean levels of sum TEQs(WHO1998) of dioxin-like mono-ortho PCBs: PCBs 105, 118, 156 and 157 (∑mo-PCBs-TEQs(WHO1998)) were highest in dairy products, chicken eggs and fish, with levels of 0.292, 0.245 and 0.254pg/g ww, respectively. The estimated daily intake (EDI) for ∑mo-PCBs-TEQs(WHO1998) was 0.74pg/kgbw/day and in the same range as in Sweden and Denmark. Fish, dairy products, eggs and meat were the main contributors to the EDI of ∑mo-PCBs-TEQs(WHO1998). The EDIs of DDTs, HCHs and HCB were several times higher than in Sweden and Denmark. Consumption of meat and poultry were important sources for intake of DDTs and HCHs, respectively. Contamination of animal feed and agricultural practice were assumed the most important causes for the results in the present study. However, increased control on maximum residue levels in food and feed may have resulted in large changes on levels and patterns of POPs in food in the studied areas.
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Czombos J, Aelterman W, Tkachev A, Martins JC, Tourwé D, Péter A, Tóth G, Fülöp F, De Kimpe N. Convenient synthesis of 3,4-methano-1,2,3, 4-tetrahydroisoquinoline-3-carboxylic acid and its derivatives as doubly constrained nonproteinogenic amino acid derivatives. J Org Chem 2000; 65:5469-75. [PMID: 10970283 DOI: 10.1021/jo9917994] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Three strategies for the synthesis of the novel, doubly constrained, 3,4-methano-1,2,3,4-tetrahydroisoquinoline-3-carboxylic acid and its derivatives were evaluated. Only cyclocondensation of the mono(triphenyl)phosphonium salt derived from 1, 2-bis(bromomethyl)benzene with N-alkoxycarbonyloxamates in 1, 2-dimethoxyethane in the presence of potassium carbonate and subsequent cyclopropanation with dimethylsulfoxonium methylide in dimethyl sulfoxide furnished suitable O- and N-protected derivatives of 3,4-methano-1,2,3,4-tetrahydroisoquinoline-3-carboxylic acid in a convenient way. A detailed 2D DQF-COSY and 2D NOESY NMR analysis of the rotational isomerism of the latter bicyclic amino acid derivatives was performed. Various O- and N-protection protocols were worked out to afford access to a whole range of new derivatives of the title amino acid, suitable for peptide synthesis.
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Polder A, Odland JO, Tkachev A, Føreid S, Savinova TN, Skaare JU. Geographic variation of chlorinated pesticides, toxaphenes and PCBs in human milk from sub-arctic and arctic locations in Russia. THE SCIENCE OF THE TOTAL ENVIRONMENT 2003; 306:179-95. [PMID: 12699926 DOI: 10.1016/s0048-9697(02)00492-8] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/13/2023]
Abstract
The concentrations of HCB, alpha-, beta- and gamma-HCH, 3 chlordanes (CHLs), p,p'-DDE, p,p'-DDD, p,p'-DDT, and 30 PCBs (polychlorinated biphenyls) were determined in 140 human milk samples from Kargopol (n=19), Severodvinsk (n=50), Arkhangelsk (n=51) and Naryan-Mar (n=20). Pooled samples were used for determination of three toxaphenes (chlorobornanes, CHBs). The concentrations of HCB, beta-HCH and p,p'-DDE in Russian human milk were 2, 10 and 3 times higher than corresponding levels in Norway, respectively, while concentrations of sum-PCBs and sum-TEQs (toxic equivalent quantities) of the mono-ortho substituted PCBs were in the same range as corresponding levels in Norway. The PCB-156 contributed most to the sum-TEQs. Highest mean concentrations of HCB (129 microg/kg milk fat) and sum-PCBs (458 microg/kg milk fat) were detected in Naryan-Mar, while highest mean concentrations of sum-HCHs (408 microg/kg milk fat), sum-CHLs (48 microg/kg milk fat), sum-DDTs (1392 microg/kg milk fat) and sum-toxaphenes (13 microg/kg milk fat) were detected in Arkhangelsk. An eastward geographic trend of increasing ratios of alpha/beta-HCH, gamma/beta-HCH, p,p'-DDT/p,p'-DDE and PCB-180/28 was observed. In all areas the levels of sum-HCHs decreased with parity (number of children born). Considerable variation in levels of the analysed organochlorines (OCs) was found in all the studied areas. Breast milk from mothers nursing their second or third child (multiparas) in Naryan-Mar showed a significant different PCB profile compared to mothers giving birth to their first child (primiparas) from the same area and to primi- and multiparas in the other areas. Both p,p'-DDE and p,p'-DDT showed a significant, but weak, negative correlation with the infants birth weight.
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Fatkhutdinova LM, Khaliullin TO, Zalyalov RR, Tkachev AG, Birch ME, Shvedova AA. Assessment of Airborn Multiwalled Carbon Nanotubes in a Manufactoring Environment. ACTA ACUST UNITED AC 2016; 11:110-116. [PMID: 28603597 DOI: 10.1134/s1995078016010055] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
This study was carried out in a factory producing multiwalled carbon nanotubes (MWCNTs) by the catalytic chemical vapor deposition method in a pyrolysis reactor. Air samples of the personal breathing areas were collected simultaneously on mixed cellulose ester filters, for analysis by transmission electron microscopy (TEM), and on high-purity quartz filters for thermal-optical analysis of elemental carbon (EC). It is found that the production of MWCNTs is accompanied by the release of the MWCNT structures in the air of different working zones. The concentration of respirable aerosol in the personal breathing areas, averaged over an 8-hour period, ranges from 0.54 to 6.11 μg/m3 based on EC. Airborne MWCNTs were found in the form of agglomerates that range in size from about 1 to 10 μm. These data are consistent with measurements in different plants by two other international groups (from the United States and Sweden) using similar methodology (TEM in combination with EC analysis). In the absence of convincing data on the potential health risks of MWCNTs, and following the principle of reasonable precautions, preventive measures should be taken to minimize exposure to these materials.
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Shulga YM, Kabachkov EN, Korepanov VI, Khodos II, Kovalev DY, Melezhik AV, Tkachev AG, Gutsev GL. The Concentration of C( sp3) Atoms and Properties of an Activated Carbon with over 3000 m 2/g BET Surface Area. NANOMATERIALS (BASEL, SWITZERLAND) 2021; 11:1324. [PMID: 34067894 PMCID: PMC8156701 DOI: 10.3390/nano11051324] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/29/2021] [Revised: 05/14/2021] [Accepted: 05/14/2021] [Indexed: 12/03/2022]
Abstract
The alkaline activation of a carbonized graphene oxide/dextrin mixture yielded a carbon-based nanoscale material (AC-TR) with a unique highly porous structure. The BET-estimated specific surface area of the material is 3167 m2/g, which is higher than the specific surface area of a graphene layer. The material has a density of 0.34 g/cm3 and electrical resistivity of 0.25 Ω·cm and its properties were studied using the elemental analysis, transmission electron microscopy (TEM), electron diffraction (ED), X-ray diffraction (XRD), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), X-ray induced Auger electron spectroscopy (XAES), and electron energy loss spectroscopy (EELS) in the plasmon excitation range. From these data, we derive an integral understanding of the structure of this material. The concentration of sp3 carbon atoms was found to be relatively low with an absolute value that depends on the measurement method. It was shown that there is no graphite-like (002) peak in the electron and X-ray diffraction pattern. The characteristic size of a sp2-domain in the basal plane estimated from the Raman spectra was 7 nm. It was also found that plasmon peaks in the EELS spectrum of AC-TR are downshifted compared to those of graphite.
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Melezhyk AV, Kotov VA, Tkachev AG. Optical Properties and Aggregation of Graphene Nanoplatelets. JOURNAL OF NANOSCIENCE AND NANOTECHNOLOGY 2016; 16:1067-1075. [PMID: 27398570 DOI: 10.1166/jnn.2016.10496] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
In the present paper, the optical density of dispersions of randomly oriented multilayer graphene nanoplatelets (GNPs) was estimated. Calculated and experimental data were compared for aqueous GNP dispersions stabilized with various surfactants. It was shown that the sonication of an expanded graphite compound (EGC) in aqueous surfactant solutions leads to the transformation of EGC worm-like particles into weak GNP aggregates which are able to pass into solution upon dilution and agitation of the system. They may be filtered and washed out of surfactants. The concentrated GNP dispersions containing these weak aggregates can be used to synthesize different graphene-based nanostructures and obtain novel composite materials.
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Vasyukova I, Gusev A, Tkachev A. Reproductive toxicity of carbon nanomaterials: a review. ACTA ACUST UNITED AC 2015. [DOI: 10.1088/1757-899x/98/1/012001] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Shalygina TA, Voronina SY, Tkachev AG, Grotskaya NN, Voronchikhin VD, Vlasov AY. Data on the synergistic effect of a hybrid filler based on graphene nanoplates and multiwalled nanotubes for increasing the thermal conductivity of an epoxy composite. Data Brief 2021; 39:107676. [PMID: 34934788 DOI: 10.1016/j.dib.2021.107676] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2021] [Revised: 11/29/2021] [Accepted: 12/01/2021] [Indexed: 11/26/2022] Open
Abstract
The dataset contains raw files related to the manuscript "The synergistic effect of a hybrid filler based on graphene nanoplates and multiwalled nanotubes for increasing the thermal conductivity of an epoxy composite" (Shalygina T.A. et al., 2021). The study presents the values of the heat capacity used to calculate the coefficients of thermal conductivity of epoxy composites by combining one-dimensional multiwalled nanotubes (MWCNTs) and two-dimensional graphene nanoplates (GNPs) in the role of a heat-conducting filler. To determine the heat capacity of materials with different concentrations of hybrid filler (GNP/MWCNT), the method of differential scanning calorimetry in the mode of the heat flux modulation was used. The analysis of the heat flux modulation samples is presented in raw and processed form. The materials scientists may apply the dataset to an in-depth study of the thermal conductivity formation mechanisms in composites doped with carbon-containing substances.
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Magee RM, Clary R, Korepanov S, Smirnov A, Garate E, Knapp K, Tkachev A. Fusion proton diagnostic for the C-2 field reversed configuration. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2014; 85:11D851. [PMID: 25430264 DOI: 10.1063/1.4892861] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Measurements of the flux of fusion products from high temperature plasmas provide valuable insights into the ion energy distribution, as the fusion reaction rate is a very sensitive function of ion energy. In C-2, where field reversed configuration plasmas are formed by the collision of two compact toroids and partially sustained by high power neutral beam injection [M. Binderbauer et al., Phys. Rev. Lett. 105, 045003 (2010); M. Tuszewski et al., Phys. Rev. Lett. 108, 255008 (2012)], measurements of DD fusion neutron flux are used to diagnose ion temperature and study fast ion confinement and dynamics. In this paper, we will describe the development of a new 3 MeV proton detector that will complement existing neutron detectors. The detector is a large area (50 cm(2)), partially depleted, ion implanted silicon diode operated in a pulse counting regime. While the scintillator-based neutron detectors allow for high time resolution measurements (∼100 kHz), they have no spatial or energy resolution. The proton detector will provide 10 cm spatial resolution, allowing us to determine if the axial distribution of fast ions is consistent with classical fast ion theory or whether anomalous scattering mechanisms are active. We will describe in detail the diagnostic design and present initial data from a neutral beam test chamber.
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Titus JB, Korepanov S, Tkachev A, Pirogov K, Knapp K. Wire calorimeter for direct neutral beam power measurements on C-2W. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2021; 92:053520. [PMID: 34243292 DOI: 10.1063/5.0043871] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/11/2021] [Accepted: 04/20/2021] [Indexed: 06/13/2023]
Abstract
The C-2W experiment produces advanced beam-driven field reversed configuration (FRC) plasmas, which are sustained in steady state utilizing variable energy neutral beams (15-40 keV, total power up to 21 MW), advanced divertors, end bias electrodes, and an active plasma control system. Since heating, current drive, and refueling from neutral beam injection are essential to FRC sustainment, it is crucial to have accurate measurements of the beam power being injected into the plasma. A new tungsten wire calorimeter has been designed, built, calibrated on a test stand, and implemented to make the first direct measurements of the time-average injected beam power into C-2W. This paper outlines the design of the diagnostic, along with calibration methods and experimental results.
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