105 research outputs found
A RESPONSE OF THE "RESERVOIR-WELL" SYSTEM TO DISTANT EARTHQUAKES
The results of joint processing of hydrogeological and seismic data obtained at the Large-Scale Research Facilities "Mid-Latitude Geophysical Observation Complex "Mikhnevo" for a 12-year observation period are presented in the article. Responses of the "reservoir-well" system to the passage of seismic waves from distant earthquakes with magnitudes of 6.3-9.0, recorded at the epicentral distances from 1863 to 16507 km, have been identified in the database. Maximum values of groundwater level variations and ground velocity under seismic impact have been determined. The power-law dependence of the levels amplitudes of confined and weakly confined aquifers on the maximum vertical ground velocity has been established. A spectral analysis of 6-hour intervals (3 hours before and 3 hours after earthquakes) of seismic and hydrogeological data was performed. The frequencies corresponding to the maximum values of ground velocity and groundwater level variations were determined in the normalized spectra. The intervals within which the extremes of the hydrogeological responses are traced at background values of the ground velocity are identified in the low-frequency range. The amplitude-frequency characteristics of the "reservoir-well" systems differ under seismic impacts at epicentral distances up to 4901 km. The responses of the systems to earthquakes at epicentral distances of 11024-14026 km are similar
LARGE-SCALE RESEARCH FACILITIES «MID-LATITUDE GEOPHYSICAL OBSERVATION COMPLEX «MIKHNEVO»
Presented here are the descriptions of the Large-Scale Research Facilities (LSRF) «Mid-latitude complex of geophysical observations "Mikhnevo"» at the Institute of Geospheres Dynamics of the Russian Academy of Sciences. The composition of the measuring complex, equipment and applied techniques are provided. The paper also presents some of the scientific results obtained at the LSRF «Mikhnevo» in recent years
Comprehensive assessment of specific antibodies on infectious activity of tick-borne encephalitis virus
Vaccines for prophylactic immunization provide the most reliable and effective protection against the vast majority of infectious diseases. Tick-borne encephalitis (TBE) represents a high-priority medical issue at the territory of the Eurasian continent. Of great importance is assessing a role of distinct antibody titers especially low titers, observed quite often in vaccinated individuals, sometimes posing obstacles in determining a threshold of seropositivity as well as the level of specific protection against TBE virus. We aimed at obtaining data to assess antiviral activity of virus-specific antibodies with distinct titer levels based on the in vitro, ex vivo and in vivo experimental studies with a highly virulent Far-Eastern strain of tick-borne encephalitis virus. The in vitro, ex vivo and in vivo comprehensive experimental studies with a highly virulent Far-Eastern strain of tick-borne encephalitis virus (TBEV) were conducted and the dynamics of antiviral activity of virus-specific antibodies at variable titers (1:100–1:3200) was measured (timeframe ranged within 1–96 hours p.i.) to provide a rationale for evaluating the antiviral immune response. It was found that the in vitro experiments demonstrated that the IgG at 1:100 titer exerted a weak anti-TBEV neutralizing effect at all time-points examined. The IgG 1:400 titer caused a 2 log PFU/mL decline in TBEV Dal strain yield at 72 h post-infection, whereas at 1:3200 titer it completely suppressed TBEV replication throughout the observation period. The ex vivo experiments with blood serum obtained from vaccinated subjects demonstrating a range of TBEV antibody titers (sera from vaccinated individuals with varying anti-TBEV antibody titers) and in vivo (outinbred white mice) experiments revealed a delayed virus elimination for antibody titers at 1:100 and 1:200 as well as rapid virus elimination (1–2 days p.i.) for antibody titers greater than 1:400. Thus, antibody titer at 1:400 may be considered as the universal anti-TBEV protection threshold. In order to properly conclude regarding the revaccination schedule it is advised to start with testing blood serum for durability of anti-TBEV immune response. Subjects with TBEV antibody titers at 1:100 and 1:200 should be strongly recommended to undergo a mandatory revaccination. Such an approach is believed to be the most effective way toward enhancing efficacy of vaccine-mediated protection against TBE
Выраженность системных воспалительных реакций у больных хронической обструктивной болезнью легких
Summary. We analyzed plasma level of an inflammatory mediator lipoxin A4 in patients with chronic obstructive pulmonary disease (COPD) which could be used as a marker of systemic inflammation in COPD patients. Relationships between the lipoxin A4 level and cellular markers of inflammation, persistent lipid peroxidation and reduced exercise tolerance have been found. Improvement in lipoxin A4 level could be an attractive contribution to rehabilitation of COPD patients and should be considered in predictive multivariable models of clinical course and in therapeutic algorithms.Резюме. Исследован уровень медиатора воспаления липоксина А4 плазмы крови при хронической обструктивной болезни легких (ХОБЛ), который может служить одним из маркеров активности системных воспалительных процессов у больных ХОБЛ. Показана взаимосвязь уровня липоксина А4 с клеточными маркерами воспаления, процессом персистирующего перекисного окисления липидов и сниженной толерантностью больных к физической нагрузке. Нормализация уровня липоксина А4 может стать перспективным направлением реабилитации больных ХОБЛ, что необходимо учитывать при разработке прогностических многофакторных моделей клинического течения заболевания и алгоритмов лечебно–профилактических мероприятий
IMMUNOPATHOGENESIS OF HEART FAILURE IN PATIENTS WITH INFECTIVE-IMMUNE MYOCARDITIS
Aim. To study quantitative parameters, specifics of functional state of the main subpopulations of peripheral blood lymphocytes of the infective-immune myocarditis patients (IIM) and postmyocarditis cardiosclerosis (PMC), and specifics of cytokine profile.Material and methods. Totally, 35 IIM patients included, and 39 with PMC. In 17 patients with IIM there was significant heart failure (HF) — III functional class (FC) by New-York Heart Association (NYHA), in 18 patients with IIM there were no signs of HF, or mild signs (0-II FC by NYHA). In 18 patients with PMC there were no signs of HF, and in 21 — there was I FC by NYHA. The controls were 10 formally healthy persons. Study of population and subpopulation contents, and lymphocytes activation markers of peripheral blood, was done with four-color laser flow cytometry using FACSCalibur equipment and relevant monoclonal antibodies (Beckton Dickinson, USA). We studied the mean cytokines concentrations characterizing Th1-, Th2- and Th17- subpopulations of the helper lymphocytes. Measurement of serum cytokines was done with the method solid-phase immune-enzyme assay with LLC “Vectro-Best” (Russia) media. Statistics was done with software PASW Statistics 18.Results. Inflammatory diseases of myocardium show the deviations of native, as acquired immunity. In IIM and PMC there was significant decrease of NKTlymphocytes, not related to the severity of HF signs and durations of the disease. Immunity activation signs in IIM group showed the increase of the early activator marker CD25 expression activation, that was marked during the first 2 weeks from the disease onset. Following, by the end of the 1st month and on the 2nd month from the disease onset, the increase of T- and non-T-lymphocytes was found with the signs of delayed activation, revealed by HLA-DR antigen expression. The activator marker patterns were differ in patients with different grade of HF severity. Concentration of interferon-γ (IFN-γ) and interleukine (IL)-4 was more than 3 times higher in IIM patients comparing to controls. There was more than 7-times higher increase of IL-17A, and concentrations of effectory cytokines of Th17-subpopulation — IL-8 and granulocyte-macrophagal colony-stimulating factor (GM CSF). The level of IFN-γ reached maximal levels during the first 2 weeks from the disease onset. Later, IFN-γ concentration declined. Opposite, serum level of IL-4 was significantly increased by the end of the 1st and on the 2nd month from disease onset. Concentrations of IL-17A, IL-8 and GM CSF in blood serum were increased during the whole 2nd week, by the end of the 1st month and on the 2nd month. Th17-cytokines concentrations were significantly increased in PMC patients. Level of IL-17A was higher than in controls almost two times, IL8 — by 51%, GM CSF — by 50%. Serum levels of IL-4, and IL-17A, IL-8 and GM CSF were higher in subgroup of PMC patients with the disease duration less than 6 months. Conclusion. Disorders of anti-infection immunity and mechanisms of selfrestriction of immune reactions do play important role in development of myocardium damage of inflammatory origin
РЕАКЦИЯ СИСТЕМ «ПЛАСТ – СКВАЖИНА» НА УДАЛЕННЫЕ ЗЕМЛЕТРЯСЕНИЯ
The results of joint processing of hydrogeological and seismic data obtained at the Large-Scale Research Facilities "Mid-Latitude Geophysical Observation Complex "Mikhnevo" for a 12-year observation period are presented in the article. Responses of the "reservoir-well" system to the passage of seismic waves from distant earthquakes with magnitudes of 6.3-9.0, recorded at the epicentral distances from 1863 to 16507 km, have been identified in the database. Maximum values of groundwater level variations and ground velocity under seismic impact have been determined. The power-law dependence of the levels amplitudes of confined and weakly confined aquifers on the maximum vertical ground velocity has been established. A spectral analysis of 6-hour intervals (3 hours before and 3 hours after earthquakes) of seismic and hydrogeological data was performed. The frequencies corresponding to the maximum values of ground velocity and groundwater level variations were determined in the normalized spectra. The intervals within which the extremes of the hydrogeological responses are traced at background values of the ground velocity are identified in the low-frequency range. The amplitude-frequency characteristics of the "reservoir-well" systems differ under seismic impacts at epicentral distances up to 4901 km. The responses of the systems to earthquakes at epicentral distances of 11024-14026 km are similar.В статье представлены результаты совместной обработки гидрогеологических и сейсмических данных, полученных на уникальной научной установке «Среднеширотный комплекс геофизических наблюдений "Михнево"» ИДГ РАН за 12-летний период наблюдений. В сформированной базе данных выделены отклики системы «пласт – скважина» на прохождение сейсмических волн от удаленных землетрясений с магнитудой 6.3–9.0, зарегистрированных на эпицентральных расстояниях от 1863 до 16507 км. Определены максимальные значения вариаций уровня подземных вод и скорости смещения грунта при сейсмическом воздействии. Установлена степенная зависимость амплитуд уровней напорного и слабонапорного водоносных горизонтов от максимальной скорости смещения грунта по вертикальной компоненте. Выполнен спектральный анализ выборки 6-часовых интервалов (3 ч до и 3 ч после землетрясения) сейсмических и гидрогеологических данных. На нормированных спектрах определены частоты, соответствующие максимальным значениям скорости смещения грунта и вариациям уровня подземных вод. В низкочастотной области выделены интервалы, в пределах которых прослежены экстремумы гидрогеологических откликов при фоновых значениях скорости смещения грунта. Амплитудно-частотные характеристики систем «пласт – скважина» при сейсмическом воздействии на эпицентральных расстояниях до 4901 км различаются. При регистрации землетрясений на эпицентральных расстояниях 11024–14026 км реакция систем подобна
Quantum Entanglement in Nitrosyl Iron Complexes
Recent magnetic susceptibility measurements for polycrystalline samples of
binuclear nitrosyl iron complexes [Fe_2(C_3H_3N_2S)_2(NO)_4] (I) and
[Fe_2(SC_3H_5N_2)_2(NO)_4] (II), suggest that quantum-mechanical entanglement
of the spin degrees of freedom exists in these compounds. Entanglement E exists
below the temperature T_E that we have estimated for complexes I and II to be
80-90 and 110-120 K, respectively. Using an expression of entanglement in terms
of magnetic susceptibility for a Heisenberg dimer, we find the temperature
dependence of the entanglement for complex II. Having arisen at the temperature
T_E, the entanglement increases monotonically with decreasing temperature and
reaches 90-95% in this complex at T=25 K, when the subordinate effects are
still small.Comment: 8 page
УНИКАЛЬНАЯ НАУЧНАЯ УСТАНОВКА «СРЕДНЕШИРОТНЫЙ КОМПЛЕКС ГЕОФИЗИЧЕСКИХ НАБЛЮДЕНИЙ «МИХНЕВО»
Presented here are the descriptions of the Large-Scale Research Facilities (LSRF) «Mid-latitude complex of geophysical observations "Mikhnevo"» at the Institute of Geospheres Dynamics of the Russian Academy of Sciences. The composition of the measuring complex, equipment and applied techniques are provided. The paper also presents some of the scientific results obtained at the LSRF «Mikhnevo» in recent years.Представлено описание уникальной научной установки ИДГ РАН «Среднеширотный комплекс геофизических наблюдений "Михнево"». Описан состав измерительного комплекса, используемая аппаратура и применяемые методики. Кратко перечислены некоторые научные результаты, полученные на УНУ СКГН «Михнево» в последние годы
Electromagnons in multiferroic RMn2O5 compounds and their microscopic origin
We summarize the existing experimental data on electromagnons in multiferroic
RMn2O5 compounds, where R denotes a rare earth ion, Y or Bi, and discuss a
realistic microscopic model of these materials based on assumption that the
microscopic mechanism of magnetically-induced ferroelectricity and
electromagnon absorption relies entirely on the isotropic Heisenberg exchange
and magnetostrictive coupling of spins to a polar lattice mode and does not
involve relativistic effects. This model explains many magnetic and optical
properties of RMn2O5 manganites, such as the spin re-orientation transition,
magnetically-induced polarisation, appearance of the electromagnon peak in the
non-collinear spin state and the polarisation of light for which this peak is
observed. We compare experimental and theoretical results on electromagnons in
RMn2O5 and RMnO3 compounds.Comment: 20 pages, 9 figures, to be published in J. Phys.: Condens. Matter,
special issue on multiferroic
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Cause of Death and Predictors of All-Cause Mortality in Anticoagulated Patients With Nonvalvular Atrial Fibrillation : Data From ROCKET AF
M. Kaste on työryhmän ROCKET AF Steering Comm jäsen.Background-Atrial fibrillation is associated with higher mortality. Identification of causes of death and contemporary risk factors for all-cause mortality may guide interventions. Methods and Results-In the Rivaroxaban Once Daily Oral Direct Factor Xa Inhibition Compared with Vitamin K Antagonism for Prevention of Stroke and Embolism Trial in Atrial Fibrillation (ROCKET AF) study, patients with nonvalvular atrial fibrillation were randomized to rivaroxaban or dose-adjusted warfarin. Cox proportional hazards regression with backward elimination identified factors at randomization that were independently associated with all-cause mortality in the 14 171 participants in the intention-to-treat population. The median age was 73 years, and the mean CHADS(2) score was 3.5. Over 1.9 years of median follow-up, 1214 (8.6%) patients died. Kaplan-Meier mortality rates were 4.2% at 1 year and 8.9% at 2 years. The majority of classified deaths (1081) were cardiovascular (72%), whereas only 6% were nonhemorrhagic stroke or systemic embolism. No significant difference in all-cause mortality was observed between the rivaroxaban and warfarin arms (P=0.15). Heart failure (hazard ratio 1.51, 95% CI 1.33-1.70, P= 75 years (hazard ratio 1.69, 95% CI 1.51-1.90, P Conclusions-In a large population of patients anticoagulated for nonvalvular atrial fibrillation, approximate to 7 in 10 deaths were cardiovascular, whereasPeer reviewe
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