Tunka-133: Results of 3 year operation Prosin, V.V.; Berezhnev, S.F.; Budnev, N.M. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
08/2014, Letnik:
756
Journal Article
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The EAS Cherenkov light array Tunka-133, with ~3km2 geometric area, is taking data since 2009. The array permits a detailed study of cosmic ray energy spectrum and mass composition in the PeV energy ...range. After a short description of the methods of EAS parameter reconstruction, we present the all-particle energy spectrum and results of studying CR composition, based on 3 seasons of array operation. In the last part of the paper, we discuss possible interpretations of the obtained results.
An efficient scheme for one-dimensional extensive air shower simulation and its implementation in the program
conex are presented. Explicit Monte Carlo simulation of the high-energy part of hadronic ...and electro-magnetic cascades in the atmosphere is combined with a numeric solution of cascade equations for smaller energy sub-showers to obtain accurate shower predictions. The developed scheme allows us to calculate not only observables related to the number of particles (shower size) but also ionization energy deposit profiles which are needed for the interpretation of data of experiments employing the fluorescence light technique. We discuss in detail the basic algorithms developed and illustrate the power of the method. It is shown that Monte Carlo, numerical, and hybrid air shower calculations give consistent results which agree very well with those obtained within the
corsika program.
The origin and nature of extreme energy cosmic rays (EECRs), which have energies above the
5
⋅
10
19
eV
—the Greisen-Zatsepin-Kuzmin (GZK) energy limit, is one of the most interesting and complicated ...problems in modern cosmic-ray physics. Existing ground-based detectors have helped to obtain remarkable results in studying cosmic rays before and after the GZK limit, but have also produced some contradictions in our understanding of cosmic ray mass composition. Moreover, each of these detectors covers only a part of the celestial sphere, which poses problems for studying the arrival directions of EECRs and identifying their sources. As a new generation of EECR space detectors, TUS (Tracking Ultraviolet Set-up), KLYPVE and JEM-EUSO, are intended to study the most energetic cosmic-ray particles, providing larger, uniform exposures of the entire celestial sphere. The TUS detector, launched on board the Lomonosov satellite on April 28, 2016 from Vostochny Cosmodrome in Russia, is the first of these. It employs a single-mirror optical system and a photomultiplier tube matrix as a photo-detector and will test the fluorescent method of measuring EECRs from space. Utilizing the Earth’s atmosphere as a huge calorimeter, it is expected to detect EECRs with energies above
10
20
eV
.
It will also be able to register slower atmospheric transient events: atmospheric fluorescence in electrical discharges of various types including precipitating electrons escaping the magnetosphere and from the radiation of meteors passing through the atmosphere. We describe the design of the TUS detector and present results of different ground-based tests and simulations.
Cardiovascular diseases (CVD) are one of the leading causes of morbidity and mortality worldwide. mtDNA (mitochondrial DNA) mutations are known to participate in the development and progression of ...some CVD. Moreover, specific types of mitochondria-mediated CVD have been discovered, such as MIEH (maternally inherited essential hypertension) and maternally inherited CHD (coronary heart disease). Maternally inherited mitochondrial CVD is caused by certain mutations in the mtDNA, which encode structural mitochondrial proteins and mitochondrial tRNA. In this review, we focus on recently identified mtDNA mutations associated with CVD (coronary artery disease and hypertension). Additionally, new data suggest the role of mtDNA mutations in Brugada syndrome and ischemic stroke, which before were considered only as a result of mutations in nuclear genes. Moreover, we discuss the molecular mechanisms of mtDNA involvement in the development of the disease.
The vascular endothelial growth factor (VEGF) family, the crucial regulator of angiogenesis, lymphangiogenesis, lipid metabolism and inflammation, is involved in the development of atherosclerosis ...and further CVDs (cardiovascular diseases). This review discusses the general regulation and functions of VEGFs, their role in lipid metabolism and atherosclerosis development and progression. These functions present the great potential of applying the VEGF family as a target in the treatment of atherosclerosis and related CVDs. In addition, we discuss several modern anti-atherosclerosis VEGFs-targeted experimental procedures, drugs and natural compounds, which could significantly improve the efficiency of atherosclerosis and related CVDs' treatment.
Development of efficient extractants for the separation of actinides and lanthanides in the technologies of nuclear fuel cycle is one of the most urgent and complex tasks in modern nuclear ...energetics. New family of 4,7-dichloro-1,10-phenanthroline-2,9-dicarboxylic acid diamides based on cyclic amines was synthesized and shown to exhibit high selectivity in the La/Am pair separation (SF (Am/La 10)) and in the Am/Eu pair separation (SF (Am/Eu 12)). It was shown that pyrrolidine derived diamide is more efficient extractant for americium, curium and lanthanides from highly acidic HNO
3
solution than its non-cyclic
N
,
N
,
N
′,
N
′-tetraalkyl analogues. The structures of synthesized compounds were studied in details by IR, NMR spectroscopy, and single crystal X-ray diffraction. According to spectroscopy data, incorporation of aromatic rings to the amide fragment of ligand leads to complex dynamic behavior in solutions what is believed to strongly affect the extraction ability of synthesized ligands.
Some unexpected "structure-extraction properties" patterns were found for new family of 1,10-phenanthroline-2,9-diamide derived ligands.
One of the stages of reproduction of SARS-CoV-2 is the S-protein glycosylation to facilitate penetration into target cells. It has been suggested that SARS-CoV-2 is able to enter erythrocytes, ...interact with heme and porphyrin, which could influence HbA1c levels. Assessment of HbA1c levels in individuals with acute COVID-19 and after recovery may show clinical relevance of this hypothesis.
To assess HbA1c levels in patients with COVID-19 in the acute phase and in early (6-8 weeks) and late (52±2 weeks) periods after recovery.
We conducted a multicenter prospective study, which included patients hospitalized in Endocrinology Research Centre and the City Clinical Hospital № 52" diagnosed with COVID-19, virus identified/ not identified. Patients were divided into three groups according to baseline HbA1c level and the presence or absence of previous history of diabetes previous history of diabetes mellitus (DM): HbA1c ≤ 6.0%, HbA1c > 6.0% and patients with DM. Patients were examined during the acute COVID-19 phase and in early (6-8 weeks) and late (52±2 weeks) periods after recovery. Oral glucose tolerance test was performed in the group with initial HbA1c > 6.0% to clarify the diagnosis.
We included 194 patients in the study. During the follow-up, 52 patients were examined in 6-8 week period: 7 with HbA1c ≤ 6.0%, 34 with HbA1c > 6.0%, 11-with previously diagnosed DM. Carbohydrate metabolism assessment in the later stages (52±2 weeks) after recovery was performed in 78 patients: 33 patients with HbA1c ≤ 6.0%, 36 patients with HbA1c > 6.0% and 9 patients with previously established diabetes. HbA1c median in patients with HbA1c ≤ 6.0% was 5.7% 5.3;5.8, with HbA1c>6.0% -6.4% 6.2; 6.6, with previously diagnosed DM-7.7% 7.2; 8.9. Statistically significant decrease in HbA1c over time 6-8 weeks after extracts were obtained in both groups of individuals without a history of DM (Wilcoxon test, p<0.05). After 52±2 weeks we observed HbA1c decrease in all three groups (Fridman test, p<0.05): in patients with HbA1c ≤ 6.0% median HbA1c was 5.55.3;5.7, with HbA1c>6.0% - 6.16.15;6.54, with previously diagnosed DM-7.8 5.83; 8.08. Development of DM after 52±2 weeks was recorded in 7.24% of all examined patients without a history of DM, which is 16.6% of the total number of patients examined in dynamics with HbA1c > 6.0%.
HbA1c elevation during the acute phase of COVID-19 may be false due to the effect of SARS-CoV-2 on hemoglobin kinetics and/or detection on the surface of the SARS-CoV-2 virion highly glycosylated S-proteins by high performance liquid chromatography determinations. Upon detection HbA1c > 6.0% in patients with COVID-19 in the active phase of the disease without concomitant hyperglycemia re-determine the level of HbA1c after recovery is recommended.
Cardiovascular diseases (CVDs) are the leading cause of death globally, representing approximately 32% of all deaths worldwide. Molecular chaperones are involved in heart protection against stresses ...and age-mediated accumulation of toxic misfolded proteins by regulation of the protein synthesis/degradation balance and refolding of misfolded proteins, thus supporting the high metabolic demand of the heart cells. Heat shock protein 90 (HSP90) is one of the main cardioprotective chaperones, represented by cytosolic
and
, mitochondrial
and ER-localised
isoforms. Currently, the main way to study the functional role of HSPs is the application of HSP inhibitors, which could have a different way of action. In this review, we discussed the recently investigated role of HSP90 proteins in cardioprotection, atherosclerosis, CVDs development and the involvements of HSP90 clients in the activation of different molecular pathways and signalling mechanisms, related to heart ageing.
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