374 research outputs found
Pharmacological correction of immune disorders in patients with chronic heart failure and ischemic heart disease
Currently, there are few data on the effect of cardiovascular drugs on the immune status of patients with heart failure (HF). This paper provides information on the impact of ß-adrenergic blocking agent (BAB), angiotensin-converting enzyme inhibitors (ACEI) on the maintenance of markers of immune inflammation in the blood, as well as on inhibition of synthesis of tumor necrosis factor-α (TNF-α) and on blocking of interaction between TNF-α and membrane receptor
Neutrophilic granulocytes in the patients with burn injury
Severe burn injury (BI) is accompanied by disturbed microcirculation, water-electrolyte and acidbase imbalance within 2-3 days after the accident, and the development of toxemia within 4-12 days. The severity of toxemia depends on the area and depth of the lesion, resorption of tissue decay products, and development of a systemic inflammatory response syndrome. In the patients suffering with deep BI sepsis, it develops in 15% of cases. Pathogenesis of critical conditions is related to the functional activity of myeloid cells, including neutrophilic granulocytes (NG). Тhe determination of NG’s dysfunctions in patients with BI is important, both for prediction of septic complications and administration of rational therapy. The aim of our work was to study the functions of neutrophils in patients with severe BI and to determine early predictors of burn-associated sepsis. The study involved 53 patients with severe BI at the mean age of 43 years (32 to 52); the area of damage was 43% (17 to 63) of the body surface, with deep-burn area of 17 (13 to 27) %. The severity of BI was assessed using the Frank index, at the average value of 74 conventional units (62 to 89). Тwo groups of patients were identified: 24 persons without sepsis, and 29 people with sepsis and severe sepsis. The studies were carried out upon admission, on the 1st, 3rd, 5th, 10th , and 20th day of the burn disease. We determined the numbers of NGs expressing CD18+, CD14+, defensin+; serum contents of soluble defensins (sDеf), IL-6, IL-8 levels (ELISA); procalcitonin, as well as luminol-mediated spontaneous аnd induced NG chemiluminescence. Тhe results of this study showed a relationship between the amounts of NGs containing antimicrobial peptides, contents of NGs expressing CD18+ adhesion molecules, activation of oxidative metabolism, IL-6 overproduction, and development of sepsis in patients with burn injury, as well as with severity of burn trauma
Pregnancy outcomes in women after arterial switch operation for transposition of the great arteries: results from ROPAC (Registry of Pregnancy and Cardiac Disease) of the European Сociety of cardiology EURObservational Research Programme
The ROPAC (Registry of Pregnancy and Cardiac disease) is an international prospective registry of pregnant women with cardiac disease, part of the European Society of Cardiology EURObservational Research Programme. Pregnancy outcomes in all women after an arterial switch procedure for transposition of the great arteries are described. The primary end point was a major adverse cardiovascular event, defined as combined end point of maternal death, supraventricular or ventricular arrhythmias requiring treatment, heart failure, aortic dissection, endocarditis, ischemic coronary events, and thromboembolic events. Altogether, 41 pregnant women (mean age, 26.7±3.9 years) were included, and there was no maternal mortality. A major adverse cardiovascular event occurred in 2 women (4.9%): heart failure in one (2.4%) and ventricular tachycardia in another (2.4%). One woman experienced fetal loss, whereas no neonatal mortality was observe
Assessment of the quality of life in elderly and senile age patients with chronic heart failure
The present study aimed to compare the QOL in patients with heart failure with mid-range ejection fraction (HFmrEF) in different age groups, taking into account gender difference
Динамика оледенения в горах юга Восточной Сибири за последние 160 лет
Changes in areas of glaciers in three South-East Siberian mountainous regions (East Sayan, Baikalsky and Kodar ridges) had been analyzed for the period since end of Little Ice Age (LIA) to the present time (about 160 years). It was determined that since the end of LIA area of these glaciers reduced, on the aver- age, by 59% (or 0.37% per a year), and their termini retreated by 550 m (3.5 m/year). At the second half of 20th century deglaciation in mountains of South- Eastern Siberia proceeded more intensive than in other Siberian regions. Современное оледенение в горах юга Восточной Сибири сосредоточено в основном на Восточном Саяне, в Байкальском хребте и на Кодаре. Последние детальные исследования ледников были выполнены на материалах аэрофотосъёмки 1950–60-х годов и требуют обновления. С использованием космических снимков среднего и высокого разрешения (Landsat ETM+, Cartosat-1, QuickBird-2, WorldView-1), полученных в 2001–2011 гг., и цифровой модели рельефа SRTM были построены карты для 51 ледника общей площадью около 15 км2. По конечно-моренным комплексам с привлечением данных лихенометрии реконструированы границы ледников для времени малого ледникового периода (МЛП). Установлено, что с конца МЛП (середина XIX в.) площадь ледников сократилась в среднем на 59% (или 0,37% за год), а их концы отступили на 550 м (3,5 м/год). Наибольшее сокращение площади установлено для ледников хр. Кодар (62%). В 2001–2011 гг. ледники сокращались на порядок быстрее, чем в 1850– 2001 гг., что, вероятно, обусловлено повышением летней температуры воздуха в 1970–2000-х годах. Дегляциация в горах юга Восточной Сибири (особенно на Кодаре) происходила во второй половине XX в. интенсивнее, чем в других районах Сибири.
Improved measurements of the energy and shower maximum of cosmic rays with Tunka-Rex
The Tunka Radio Extension (Tunka-Rex) is an array of 63 antennas located in
the Tunka Valley, Siberia. It detects radio pulses in the 30-80 MHz band
produced during the air-shower development. As shown by Tunka-Rex, a sparse
radio array with about 200 m spacing is able to reconstruct the energy and the
depth of the shower maximum with satisfactory precision using simple methods
based on parameters of the lateral distribution of amplitudes. The LOFAR
experiment has shown that a sophisticated treatment of all individually
measured amplitudes of a dense antenna array can make the precision comparable
with the resolution of existing optical techniques. We develop these ideas
further and present a method based on the treatment of time series of measured
signals, i.e. each antenna station provides several points (trace) instead of a
single one (amplitude or power). We use the measured shower axis and energy as
input for CoREAS simulations: for each measured event we simulate a set of
air-showers with proton, helium, nitrogen and iron as primary particle (each
primary is simulated about ten times to cover fluctuations in the shower
maximum due to the first interaction). Simulated radio pulses are processed
with the Tunka-Rex detector response and convoluted with the measured signals.
A likelihood fit determines how well the simulated event fits to the measured
one. The positions of the shower maxima are defined from the distribution of
chi-square values of these fits. When using this improved method instead of the
standard one, firstly, the shower maximum of more events can be reconstructed,
secondly, the resolution is increased. The performance of the method is
demonstrated on the data acquired by the Tunka-Rex detector in 2012-2014.Comment: Proceedings of the 35th ICRC 2017, Busan, Kore
Tunka-Rex: energy reconstruction with a single antenna station (ARENA 2016)
The Tunka-Radio extension (Tunka-Rex) is a radio detector for air showers in
Siberia. From 2012 to 2014, Tunka-Rex operated exclusively together with its
host experiment, the air-Cherenkov array Tunka-133, which provided trigger,
data acquisition, and an independent air-shower reconstruction. It was shown
that the air-shower energy can be reconstructed by Tunka-Rex with a precision
of 15\% for events with signal in at least 3 antennas, using the radio
amplitude at a distance of 120\,m from the shower axis as an energy estimator.
Using the reconstruction from the host experiment Tunka-133 for the air-shower
geometry (shower core and direction), the energy estimator can in principle
already be obtained with measurements from a single antenna, close to the
reference distance. We present a method for event selection and energy
reconstruction, requiring only one antenna, and achieving a precision of about
20\%. This method increases the effective detector area and lowers thresholds
for zenith angle and energy, resulting in three times more events than in the
standard reconstruction
Signal recognition and background suppression by matched filters and neural networks for Tunka-Rex
The Tunka Radio Extension (Tunka-Rex) is a digital antenna array, which
measures the radio emission of the cosmic-ray air-showers in the frequency band
of 30-80 MHz. Tunka-Rex is co-located with TAIGA experiment in Siberia and
consists of 63 antennas, 57 of them are in a densely instrumented area of about
1 km\textsuperscript{2}. In the present work we discuss the improvements of the
signal reconstruction applied for the Tunka-Rex. At the first stage we
implemented matched filtering using averaged signals as template. The
simulation study has shown that matched filtering allows one to decrease the
threshold of signal detection and increase its purity. However, the maximum
performance of matched filtering is achievable only in case of white noise,
while in reality the noise is not fully random due to different reasons. To
recognize hidden features of the noise and treat them, we decided to use
convolutional neural network with autoencoder architecture. Taking the recorded
trace as an input, the autoencoder returns denoised trace, i.e. removes all
signal-unrelated amplitudes. We present the comparison between standard method
of signal reconstruction, matched filtering and autoencoder, and discuss the
prospects of application of neural networks for lowering the threshold of
digital antenna arrays for cosmic-ray detection.Comment: ARENA2018 proceeding
Current Status and New Challenges of The Tunka Radio Extension
The Tunka Radio Extension (Tunka-Rex) is an antenna array spread over an area
of about 1~km. The array is placed at the Tunka Advanced Instrument for
cosmic rays and Gamma Astronomy (TAIGA) and detects the radio emission of air
showers in the band of 30 to 80~MHz. During the last years it was shown that a
sparse array such as Tunka-Rex is capable of reconstructing the parameters of
the primary particle as accurate as the modern instruments. Based on these
results we continue developing our data analysis. Our next goal is the
reconstruction of cosmic-ray energy spectrum observed only by a radio
instrument. Taking a step towards it, we develop a model of aperture of our
instrument and test it against hybrid TAIGA observations and Monte-Carlo
simulations. In the present work we give an overview of the current status and
results for the last five years of operation of Tunka-Rex and discuss prospects
of the cosmic-ray energy estimation with sparse radio arrays.Comment: Proceedings of E+CRS 201
Towards a cosmic-ray mass-composition study at Tunka Radio Extension (ARENA 2016)
The Tunka Radio Extension (Tunka-Rex) is a radio detector at the TAIGA
facility located in Siberia nearby the southern tip of Lake Baikal. Tunka-Rex
measures air-showers induced by high-energy cosmic rays, in particular, the
lateral distribution of the radio pulses. The depth of the air-shower maximum,
which statistically depends on the mass of the primary particle, is determined
from the slope of the lateral distribution function (LDF). Using a
model-independent approach, we have studied possible features of the
one-dimensional slope method and tried to find improvements for the
reconstruction of primary mass. To study the systematic uncertainties given by
different primary particles, we have performed simulations using the CONEX and
CoREAS software packages of the recently released CORSIKA v7.5 including the
modern high-energy hadronic models QGSJet-II.04 and EPOS-LHC. The simulations
have shown that the largest systematic uncertainty in the energy deposit is due
to the unknown primary particle. Finally, we studied the relation between the
polarization and the asymmetry of the LDF.Comment: ARENA proceedings, 4 pages, updated reference
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