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Sixteen priority polycyclic aromatic hydrocarbons (PAHs) were qualitatively and quantitatively assessed by high-performance liquid chromatography with fluorescence detection in snow samples collected at 46 sites of Arkhangelsk as a world's largest city above 64 degrees north latitude. The average, maximum and minimum PAH concentrations in snow were 168, 665, and 16 ng/kg, respectively. The average toxic equivalent value in benzo(a)pyrene units was 3.6 ng/kg, which is three-fold lower than the established maximum permissible concentration and considered an evidence of a low/moderate level of snow pollution with PAHs. The pollution origin was assessed using specific markers based on PAHs ratios in the studied samples. The pyrogenic sources of PAH emission were predominate, whereas the significant contributions from both transport and solid fuel combustion were observed. Benzo(a)pyrene concentrations are highly correlated with the levels of other PAHs with higher molecular weights.
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Anthropogenic pollution of the Arctic atmosphere is of great interest due to the vulnerability of the Arctic ecosystems, as well as the processes of global transport and accumulation of atmospheric aerosols at high latitudes under conditions of cold climate. The present work throws light upon chemical composition of Arctic snow as a natural deposition matrix for atmospheric semi-volatile pollutants taken from the northernmost Arctic archipelago - Franz Josef Land, which is least affected by local sources of pollution and being a unique unstudied environmental object. The used methodology involved the liquid-liquid extraction of snow samples with dichloromethane and combination of targeted and non-targeted analyses of semi-volatile organic compounds with comprehensive two-dimensional gas chromatography - high-resolution mass spectrometry. While almost none of the known priority pollutants (except three dialkylphthalates) were identified in the studied samples, non-targeted screening revealed a specific class of biomass burning biomarkers - fatty amides with oleamide being the major component among them. Some peculiar organic pollutants (N,N-dimethylcyclohexylamine and N,N-dimethylbenzylamine) were identified in few samples. First results on the semi volatile pollutants in Franz Joseph Land snow were obtained using the most reliable GC × GC-HRMS non-target analysis.
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Contaminantes Atmosféricos/análisis , Nieve , Regiones Árticas , Atmósfera , Ecosistema , Monitoreo del AmbienteRESUMEN
Environmental contamination of the Arctic has widely been used as a worldwide pollution marker. Various classes of organic pollutants such as pesticides, personal care products, PAHs, flame retardants, biomass burning markers, and many others emerging contaminants have been regularly detected in Arctic samples. Although numerous papers have been published reporting data from the Canadian, Danish, and Norwegian Arctic regions, the environmental situation in Russian Arctic remains mostly underreported. Snow analysis is known to be used for monitoring air pollution in the regions with cold climate in both short-term and long-term studies. This paper presents the results of a nontargeted study on the semivolatile organic compounds detected and identified in snow samples collected at the Russian Artic Archipelago Novaya Zemlya in June 2016. Gas chromatography coupled to a high-resolution time-of-flight mass spectrometer enabled the simultaneous detection and quantification of a variety of pollutants including those from the US Environmental Protection Agency (EPA) priority pollutants list, emerging contaminants (plasticizers, flame retardants-only detection), as well as the identification of novel Arctic organic pollutants, (e.g., fatty acid amides and polyoxyalkanes). The possible sources of these novel pollutants are also discussed. GC-HRMS enabled the detection and identification of emerging contaminants and novel organic pollutants in the Arctic, e.g., fatty amides and polyoxyalkanes.
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Monitoreo del Ambiente , Contaminantes Ambientales/análisis , Nieve/química , Compuestos Orgánicos Volátiles/análisis , Regiones Árticas , Canadá , Contaminación Ambiental/análisis , Contaminación Ambiental/estadística & datos numéricos , Retardadores de Llama/análisis , Islas , Noruega , Plaguicidas/análisis , Hidrocarburos Policíclicos Aromáticos/análisis , Federación de RusiaRESUMEN
We describe a magnetic field sensor based on a spin wave interferometer. Its sensing element consists of a magnetic cross junction with four micro-antennas fabricated at the edges. Two of these antennas are used for spin wave excitation while two other antennas are used for detection of the inductive voltage produced by the interfering spin waves. Two waves propagating in the orthogonal arms of the cross may accumulate significantly different phase shifts depending on the magnitude and direction of the external magnetic field. This phenomenon is utilized for magnetic field sensing. The sensitivity attains its maximum under the destructive interference condition, where a small change in the external magnetic field results in a drastic increase of the inductive voltage, as well as in the change of the output phase. We report experimental data obtained for a micrometer scale Y3Fe2(FeO4)3 cross structure. The change of the inductive voltage near the destructive interference point exceeds 40 dB per 1 Oe. The phase of the output signal exhibits a π-phase shift within 1 Oe. The data are collected at room temperature. Taking into account the low thermal noise in ferrite structures, we estimate that the maximum sensitivity of the spin wave magnetometer may exceed attotesla.
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AIM: To estimate the importance of new algorithm introducing of PDP diagnostics in practice of NEFU medical institute Clinic in detection of severity level and predicting of clinical course. MATERIALS AND METHODS: 50 people with sensory-motor PDP form among patients with 2 type diabetes were examined on the basis of Clinic of NEFU medical institute. Patients have been divided into 2 groups by disease duration: the first groups were patients with duration of disease till 10 years, the second group--more than 10 years. Diagnostics methods: clinical neurologic, neurophysiological. RESULTS: Patients underwent polymodal sensitivity analysis, computer pallesteziometry, stabilometry, electroneuromyography. The dependence of clinical neurophysiological PDP parametres from severity of the duration of type 2 diabetes has been revealed. CONCLUSION: Thus, dependence of clinical-neurophysiological parametres of PDP severity from the duration of 2 type diabetes has been revealed. The new algorithm raised efficacy of clinical-neurophysiological PDP diagnostics and helped the predicting of the clinical course.
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Algoritmos , Diabetes Mellitus Tipo 2/complicaciones , Neuropatías Diabéticas/diagnóstico , Neuropatías Diabéticas/etiología , Predicción/métodos , Adulto , Anciano , Animales , Femenino , Humanos , Masculino , Persona de Mediana Edad , Reproducibilidad de los Resultados , Factores de TiempoRESUMEN
The paper describes the results of a sociological study of delivery of healthcare in the Republic of Altai to search for ways to improve its quality and to provide access to the local population. Analysis was made with regard to an interdisciplinary, comprehensive approach to considering the range of problems associated with not only the health of local residents and identifying risk factors leading to diseases, but also by determining the possibilities that could promote the minimization of causes that have a considerable impact on the occurrence of diseases and also hamper healthcare delivery in the human settlements of Gornyi Altai, which are difficult of access. The investigation has used sociological and statistical methods. It has been ascertained that the available healthcare forces and means should be today employed at the regional level, by applying the principles of necessary sufficiency in conjunction with the local population's social motivation to be involved in the activity associated with the rendering of medical services. In addition, it is necessary to systemically use mobile medical units as a significant factor for the optimization of medical care to the population living in Russia's regions which are difficult of access.
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Altitud , Áreas de Influencia de Salud , Clima , Atención a la Salud , Calidad de la Atención de Salud , Atención a la Salud/economía , Atención a la Salud/organización & administración , Atención a la Salud/normas , Reforma de la Atención de Salud , Disparidades en el Estado de Salud , Humanos , Siberia , Factores SocioeconómicosAsunto(s)
Frecuencia Cardíaca/fisiología , Hipertiroidismo/cirugía , Marcapaso Artificial , Cuidados Preoperatorios/métodos , Tiroidectomía/métodos , Complejos Prematuros Ventriculares/terapia , Anciano , Electrocardiografía Ambulatoria , Femenino , Estudios de Seguimiento , Humanos , Hipertiroidismo/complicaciones , Complejos Prematuros Ventriculares/etiología , Complejos Prematuros Ventriculares/fisiopatologíaRESUMEN
BaBiO3 is a material where Bi4+ ions with half-filled 6s-states form an alternating set of Bi3+ and Bi5+ ions resulting in a charge ordered insulator. The charge ordering is accompanied by breathing distortion of the BiO6 octahedra (extension and contraction of the Bi-O bond lengths). Standard density functional theory (DFT) calculations fail to obtain the crystal structure instability caused by the pure breathing distortions. Combining effects of the breathing distortions and tilting of the BiO6 octahedra allows DFT to reproduce qualitatively an experimentally observed insulator with monoclinic crystal structure but strongly underestimates the breathing distortion parameter and energy gap values. In the present work we reexamine the BaBiO3 problem within the GGA + U method using a Wannier function basis set for the Bi 6s-band. Due to the high oxidation state of bismuth in this material, the Bi 6s-symmetry Wannier function is predominantly extended spatially on surrounding oxygen ions and hence differs strongly from a pure atomic 6s-orbital. That is in sharp contrast to transition metal oxides (with exclusion of high oxidation state compounds) where the major part of the d-band Wannier function is concentrated on the metal ion and a pure atomic d-orbital can serve as a good approximation. The GGA + U calculation results agree well with experimental data, in particular with experimental crystal structure parameters and energy gap values. Moreover, the GGA + U method allows one to reproduce the crystal structure instability due to the pure breathing distortions without octahedra tilting.
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We employ the combination of the density functional theory and the dynamical mean-field theory to investigate the electronic structure and magnetic properties of SrCoO(3), monocrystals of which were prepared recently. Our calculations lead to a ferromagnetic metal in agreement with experiment. We find that, contrary to some suggestions, the local moment in SrCoO(3) does not arise from intermediate spin state, but is a result of coherent superposition of many different atomic states. We discuss how the attribution of magnetic response to different atomic states in solids with local moments can be quantified.
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Ab initio analyses of A(2)IrO(4) (A=Sr,Ba) are presented. Effective Hubbard-type models for Ir 5d t(2g) manifolds downfolded from the global band structure are solved based on the dynamical mean-field theory. The results for A=Sr and Ba correctly reproduce paramagnetic metals undergoing continuous transitions to insulators below the Néel temperature T(N). These compounds are classified not into Mott insulators but into Slater insulators. However, the insulating gap opens by a synergy of the Néel order and significant band renormalization, which is also manifested by a 2D bad metallic behavior in the paramagnetic phase near the quantum criticality.
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The LDA+DMFT (local density approximation combined with dynamical mean-field theory) computation scheme has been used to calculate spectral properties of LaFeAsO-the parent compound of the new high-T(c) iron oxypnictides. The average Coulomb repulsion [Formula: see text] and Hund's exchange J parameters for iron 3d electrons were calculated using the first-principles constrained density functional theory scheme in the Wannier functions formalism. Resulting values strongly depend on the number of states taken into account in the calculations: when the full set of O-2p, As-4p and Fe-3d orbitals and the corresponding bands are included, the interaction parameters [Formula: see text] eV and J = 0.8 eV are obtained. In contrast, when the basis set is restricted to the Fe-3d orbitals and bands only, the calculation gives much smaller values of [Formula: see text] eV, J = 0.5 eV. Nevertheless, DMFT calculations with both parameter sets and the corresponding basis sets result in a weakly correlated electronic structure that is in agreement with the experimental x-ray and photoemission spectra.
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Three events for the decay K+-->pi+ nunu have been observed in the pion momentum region below the K+-->pi+pi0 peak, 140 < Ppi < 199 MeV/c, with an estimated background of 0.93+/-0.17(stat.) -0.24+0.32(syst.) events. Combining this observation with previously reported results yields a branching ratio of B(K+-->pi+ nunu) = (1.73(-1.05)+1.15) x 10(-10) consistent with the standard model prediction.
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The article presents a classic case of primary hyperparathyroidism with a variety of clinical "masks" and diagnoses.
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Adenoma , Hiperparatiroidismo Primario , Hormona Paratiroidea/sangre , Neoplasias de las Paratiroides , Adenoma/sangre , Adenoma/complicaciones , Adenoma/diagnóstico , Adenoma/terapia , Adulto , Diagnóstico Diferencial , Humanos , Hiperparatiroidismo Primario/sangre , Hiperparatiroidismo Primario/etiología , Hiperparatiroidismo Primario/terapia , Masculino , Neoplasias de las Paratiroides/sangre , Neoplasias de las Paratiroides/complicaciones , Neoplasias de las Paratiroides/diagnóstico , Neoplasias de las Paratiroides/terapiaRESUMEN
We report high-resolution high-energy photoemission spectra together with parameter-free LDA + DMFT (local density approximation + dynamical mean-field theory) results for Sr1-xCaxVO3, a prototype 3d(1) system. In contrast to earlier investigations the bulk spectra are found to be insensitive to x. The good agreement between experiment and theory confirms the bulk sensitivity of the high-energy photoemission spectra.
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An additional event near the upper kinematic limit for K+-->pi(+)nunu; has been observed by experiment E949 at Brookhaven National Laboratory. Combining previously reported and new data, the branching ratio is B(K+-->pi(+)nunu;)=(1.47(+1.30)(-0.89))x10(-10) based on three events observed in the pion momentum region 211
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A simple method of quantitative evaluation of modified human serum albumin (SA) was suggested for the use in clinical practice. It is based on the natural ability of modified SA to form complexes with endogenous urea. An SA content, which lost its secondary and tertiary structures, is indirectly predetermined by the quantity of urea bound with protein that is biochemically determined after hydrolysis of the studied sample of partially purified SA. The clinical value of the parameter that is being determined is under discussion.
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Albúmina Sérica/análisis , Humanos , Unión Proteica , Conformación Proteica , Desnaturalización Proteica , Albúmina Sérica/metabolismo , Urea/metabolismoRESUMEN
We report the first observation of a charm-strange meson D(+)(sJ)(2632) at a mass of 2632.5+/-1.7 MeV/c(2) in data from SELEX, the charm hadro-production experiment E781 at Fermilab. This state is seen in two decay modes, D(+)(s)eta and D0K+. In the D(+)(s)eta decay mode we observe a peak with 101 events over a combinatoric background of 54.9 events at a mass of 2635.4+/-3.3 MeV/c(2). There is a corresponding peak of 21 events over a background of 6.9 at 2631.5+/-2.0 MeV/c(2) in the decay mode D0K+. The decay width of this state is <17 MeV/c(2) at 90% confidence level. The relative branching ratio Gamma(D0K+)/Gamma(D(+)(s)eta) is 0.14+/-0.06. The mechanism that keeps this state narrow is unclear. Its decay pattern is also unusual, being dominated by the D(+)(s)eta decay mode.
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We investigate nonequilibrium noise in a diffusive Andreev interferometer, in which currents emerging from two normal metal/superconductor (N-S) interfaces can interfere. We observe a modulation of the shot noise when the phase difference between the two N-S interfaces is varied by a magnetic flux. This is the signature of phase-sensitive fluctuations in the normal metal. The effective charge inferred from the shot noise measurement is close to q(eff) = 2e but shows phase-dependent deviations from 2e at finite energy, which we interpret as being due to pair correlations. Experimental data are in good agreement with predictions based on an extended Keldysh Green's function approach.
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We observe a signal for the doubly charmed baryon Xi(+)(cc) in the charged decay mode Xi(+)(cc)-->Lambda(+)(c)K-pi(+) in data from SELEX, the charm hadroproduction experiment at Fermilab. We observe an excess of 15.9 events over an expected background of 6.1+/-0.5 events, a statistical significance of 6.3sigma. The observed mass of this state is 3519+/-1 MeV/c(2). The Gaussian mass width of this state is 3 MeV/c(2), consistent with resolution; its lifetime is less than 33 fs at 90% confidence.
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We report new precision measurements of the lifetimes of the Lambda(+)(c) and D0 from SELEX, the charm hadroproduction experiment at Fermilab. Based upon 1630 Lambda(+)(c) and 10 210 D0 decays we observe lifetimes of tau[Lambda(+)(c)] = 198.1+/-7.0+/-5.6 fs and tau[D0] = 407.9+/-6.0+/-4.3 fs.