83 research outputs found

    On the Relationship Between the Optical Emission-Line and X-ray Luminosities in Seyfert 1 Galaxies

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    We have explored the relationship between the [O III] λ\lambda5007 and the 2--10 keV luminosities for a sample of Broad- and Narrow-Line Seyfert 1 galaxies (BLSy1 and NLSy1, respectively). We find that both types of Seyferts span the same range in luminosity and possess similar [O III]/X-ray ratios. The NLSy1s are more luminous than BLSy1s, when normalized to their central black hole masses, which is attributed to higher mass accretion rates. However, we find no evidence for elevated [O III]/X-ray ratios in NLSy1s, which would have been expected if they had excess EUV continuum emission compared to BLSy1s. Also, other studies suggest that the gas in narrow-line regions (NLR) of NLSy1s and NLSy1s span a similar range in ionization, contrary to what is expected if those of the former are exposed to a stronger flux of EUV radiation. The simplest interpretation is that, like BLSy1s, a large EUV bump is not present in NLSy1s. However, we show that the [OIII]/X-ray ratio can be lowered as a result of absorption of the ionizing continuum by gas close to the central source, although there is no evidence that intrinsic line-of-sight absorption is more common among NLSy1s, as would be expected if there were a larger amount of circumnuclear gas. Other possible explanations include: 1) anisotropic emission of the ionizing radiation, 2) higher gas densities in the NLR of NLSy1s, resulting in lower average ionization, or 3) the presence of strong winds in the the nuclei of NLSy1s which may drive off much of the gas in the narrow-line region, resulting in lower cover fraction and weaker [O III] emission.Comment: 18 pages, including 3 figures, 2 tables. Accepted for publication in The Astrophysical Journa

    Development of West-European PM2.5 and NO2 land use regression models incorporating satellite-derived and chemical transport modelling data

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    Satellite-derived (SAT) and chemical transport model (CTM) estimates of PM2.5 and NO2 are increasingly used in combination with Land Use Regression (LUR) models. We aimed to compare the contribution of SAT and CTM data to the performance of LUR PM2.5 and NO2 models for Europe. Four sets of models, all including local traffic and land use variables, were compared (LUR without SAT or CTM, with SAT only, with CTM only, and with both SAT and CTM). LUR models were developed using two monitoring data sets: PM2.5 and NO2 ground level measurements from the European Study of Cohorts for Air Pollution Effects (ESCAPE) and from the European AIRBASE network. LUR PM2.5 models including SAT and SAT+CTM explained ~60% of spatial variation in measured PM2.5 concentrations, substantially more than the LUR model without SAT and CTM (adjR(2): 0.33-0.38). For NO2 CTM improved prediction modestly (adjR(2): 0.58) compared to models without SAT and CTM (adjR(2): 0.47-0.51). Both monitoring networks are capable of producing models explaining the spatial variance over a large study area. SAT and CTM estimates of PM2.5 and NO2 significantly improved the performance of high spatial resolution LUR models at the European scale for use in large epidemiological studies

    Влияние лечения тиотриазолином на состояние перекисного окисления липидов и уровни иммуновоспалительных и вазоактивных эндотелиальных факторов у больных с хронической сердечной недостаточностью и helicobacter pylori-негативными гастропатиями

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    Показано, что включение в схему патогенетического лечения больных с ХСН, hp-негативной гастропатией и умеренным или высоким риском сердечно-сосудистых осложнений (ССО) антиоксиданта тиотриазолина сопровождается достоверно более выраженными позитивными эффектами на процессы перекисного окисления липидов и содержание в крови иммуновоспалительных и вазоактивных эндотелиальных факторов по сравнению с динамикой при лечении без использования тиотриазолина, причем степень положительной динамики у больных с высоким риском ССО достоверно больше.Показано, що включення у схему патогенетичного лікування хворих із ХСН, hр-негативною гастропатією і з помірним або високим ризиком серцево-судинних ускладнень (ССУ) антиоксиданта тіотриазоліна супроводжується достовірно більш вираженими позитивними ефектами на процеси перекисного окислення ліпідів та вміст у крові імунозапальних і вазоактивних ендотеліальних факторів порівняно з динамікою при лікуванні без використання тіотриазоліну, причому ступінь позитивної динаміки у хворих із високим ризиком ССУ достовірно більший.It is shown that the use of tiotriazolin in the scheme of pathogenetic treatment of patients with chronic heart failure, Hp-negative gastropathy, and moderate or high risk of cardiovascular complications (CVC) is accompanied by significantly higher positive effect on the processes of lipid peroxidation and the amount of immune inflammation and vasoactive endothelial factors in the blood when compared with the dynamics at treatment without the use of tiotriazolin, the degree of positive dynamics in patients with a high risk of CVC being significantly higher

    High-Resolution Gas Chromatography-Tandem Mass Spectrometry: A Sensitive Analytical Technique Suitable for the Study of Atmospheric Processes of Polychlorinated Biphenyls and Dibenzo-p-Dioxins/Furans

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    The trace-level environmental determination of polychlorinated biphenyls (PCBs) and 2,3,7,8-substituted polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) requires the use of delicate fractionation and analytical techniques such as high-resolution gas chromatography coupled with high-resolution mass spectrometry. The analytical requirements are even higher if atmospheric physicochemical processes of these persistent organic compounds (POPs) are to be studied in remote areas, where concentrations are very low. The optimization of a fractionation method, and of the high-resolution gas chromatography/ion trap tandem mass spectrometry system instrumental parameters enabled us to establish the optimum conditions for the determination of atmospheric PCBs and PCDD/Fs at the low pg or even fg m-3 level. By using this analytical procedure, we accomplished the reliable determination of ca. 54 PCBs and 17 PCDD/Fs individual congeners, of different chlorination level, in the gas and particulate phase of atmospheric aerosol samples collected from the Eastern Mediterranean basin. Furthermore, we were also able to study the atmospheric physicochemical and loss processes of PCBs, such as gas-particle partitioning, wet and dry deposition, and PCBs reaction with hydroxyl radicals
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