39 research outputs found
Atmospheric muon flux at PeV energies
In the near future the energy region above few hundreds of TeV may really be
accessible for measurements of the atmospheric muon spectrum by the IceCube
array. Therefore one expects that muon flux uncertainties above 50 TeV, related
to a poor knowledge of charm production cross sections and insufficiently
examined primary spectra and composition, will be diminished. We give
predictions for the very high-energy muon spectrum at sea level, obtained with
the three hadronic interaction models, taking into account also the muon
contribution due to decays of the charmed hadrons.Comment: 8 pages, 3 figures. The version published in Int. J. Mod. Phys.
Prompt muon contribution to the flux underwater
We present high energy spectra and zenith-angle distributions of the
atmospheric muons computed for the depths of the locations of the underwater
neutrino telescopes. We compare the calculations with the data obtained in the
Baikal and the AMANDA muon experiments. The prompt muon contribution to the
muon flux underwater due to recent perturbative QCD-based models of the charm
production is expected to be observable at depths of the large underwater
neutrino telescopes. This appears to be probable even at rather shallow depths
(1-2 km), provided that the energy threshold for muon detection is raised above
TeV.Comment: 7 pages, RevTeX, 7 eps figures, final version to be published in
Phys.Rev.D; a few changes made in the text and the figures, an approximation
formula for muon spectra at the sea level, the muon zenith-angle distribution
table data and references adde
ИСПОЛЬЗОВАНИЕ ГЕНЕТИЧЕСКИХ РЕСУРСОВ В СЕЛЕКЦИИ ОВОЩНЫХ И БАХЧЕВЫХ КУЛЬТУР
The analysis of the modern homeland assortment of vegetable crops is given. The donors of the most important traits and the accessions of vegetable and melon crops perspective for breeding from the VIR collection are shown. The short characteristic of the varieties is given.В статье дан анализ отечественного сортимента овощных культур. Приведены донорыселекционно ценных признаков и перспективные для использования в селекции сортообразцы овощных и бахчевых культур из коллекции ВИР. Дана краткая характеристика сортов овощных культур селекции ВИР
Structure and significance of cytogenetic abnormalities in adult patients with Ph-negative acute lymphoblastic leukemia
Objective. To evaluate occurrence, variety, structural peculiarities and prognostic meaning of cytogenetic abnormalities in adult patients with Ph-negative acute lymphoblastic leukemia (ALL) receiving therapy according to ALL-2009 protocol. Materials and methods. The study included 115 adult patients with firstly diagnosed Ph-negative ALL: 58 male and 57 female aged from 15 to 61 years (mean age 26.5 years), who underwent treatment from September 2009 to September 2015 in National Medical Research Center for Hematology MH RF (n=101) and in hematology departments of regional hospitals (n=14). All patients received therapy of ALL-2009 protocol (ClinicalTrials.gov, NCT01193933). The median follow-up was 24.5 months (0.2-94.4 months). As a part of the study results of a standard cytogenetic assay (SCA) were analyzed and fluorescence hybridization in situ (FISH) with the use of DNA-probes was performed on archived biological material for structural changes in gene locuses MLL/t(11q23), с-MYC/t(8q24), TP53/ deletion 17p13, CDKN2A/ deletion 9p21, translocation t(1;19)/E2A-PBX1 и t(12;21)/ETV6-RUNX1; iAMP21 identification. Results. Karyotype was defined using SCA in 86% of patients. Normal karyotype was found in 48.5% of them, chromosome aberrations in 51.5% (structural changes were found in 19.2%, hyperploidy in 27.2%, and hypoploidy in 5.1%). In 17.2% of patients complex karyotype abnormalities were found. With the use of FISH technique aberrations were found in 67% of patients: 9p21/CDKN2A deletion in 24.3%, MLL/t(11q23) gene abnormalities in 7.8%, 17p13/TP53 deletion in 5.2%, abnormalities of c-MYC/t(8q24) in 1.7%, t(1;19)/E2A-PBX1 in 0.8%, and iAMP21 in 0.8%, other abnormalities (additional signals/absence of signals from gene locuses) in 26.4%, t(12;21)/ETV6-RUNX1 was not found. FISH technique use in addition to SCA allows to increase aberrant karyotype location from 51.5 to 67%. A statistically significant correlation of 9p21/CDKN2A deletion with high serum lactate dehydrogenase activity (p=0.02); MLL/t(11q23) gene abnormalities - with leucocytosis and high blast cells level in blood (p=0.0016), hyperploidy - with normal leukocyte count (p=0.02) was shown. In groups with different cytogenetic abnormalities no statistically significant differences of treatment with ALL-2009 protocol were found (in terms of complete remission, early mortality and treatment resistance). When connection of cytogenetic abnormalities and their combinations with long-term results were analyzed according to ALL-2009 protocol, only two characteristics - MLL/t(11q23) and c MYC/t(8q24) gene abnormalities had a statistically significant influence on disease-free survival (HR - 176.9;
СПОСОБЫ УПРАВЛЕНИЯ СТРУКТУРНЫМ СОСТОЯНИЕМ ЗАЩИТНЫХ ВАКУУМНО-ДУГОВЫХ ПОКРЫТИЙ
The paper has investigated two methods pertaining to formation of protective nano-structural vacuum coatings while using separated plasma flows. A comparatively technologically simple control method for crystallite size in the direction of coating growth has been developed in the paper. The method is based on the deposition of individual thin layers of high-melting compounds of transition metals from separated plasma flows and periodical bombardment of condensates formed by an ion flow. The executed X-ray diffraction analysis has shown that an application of the given method makes it possible to reduce size of a coherent-scattering area up to 10–15 nm and ensure an increase of micro-hardness and corrosion resistance of the deposited coatings. Nano-crystalline Ti–Cr–N coatings with crystallite size of 10–20 nm have been obtained while applying a vacuum-arc deposition technique from separated plasma flows. The paper demonstrates that purposeful alloying improves operational coating properties that allows to use the coatings as protective layers which are deposited on the working surfaces of cutting tools.Исследованы два способа формирования защитных наноструктурных вакуумных покрытий с использованием сепарированных плазменных потоков. Разработан сравнительно простой в технологическом исполнении способ управления размерами кристаллитов в направлении роста покрытия, основанный на осаждении индивидуальных тонких слоев тугоплавких соединений переходных металлов из сепарированных плазменных потоков и периодической бомбардировкой сформированных конденсатов потоком ионов. Проведенные рентгеноструктурные исследования показали, что применение данного способа позволило как снизить размер областей когерентного рассеяния до 10–15 нм, так и обеспечить повышение микротвердости и коррозионной стойкости сформированных покрытий. Методом вакуумно-дугового осаждения из сепарированных плазменных потоков получены нанокристаллические покрытия Ti–Cr–N c размером кристаллитов 10–20 нм. Установлено, что целенаправленное легирование улучшает эксплуатационные свойства покрытий, что позволяет использовать их в качестве защитных слоев, осажденных на рабочие поверхности режущих инструментов
Atmospheric Muon Flux at Sea Level, Underground, and Underwater
The vertical sea-level muon spectrum at energies above 1 GeV and the
underground/underwater muon intensities at depths up to 18 km w.e. are
calculated. The results are particularly collated with a great body of the
ground-level, underground, and underwater muon data. In the hadron-cascade
calculations, the growth with energy of inelastic cross sections and pion,
kaon, and nucleon generation in pion-nucleus collisions are taken into account.
For evaluating the prompt muon contribution to the muon flux, we apply two
phenomenological approaches to the charm production problem: the recombination
quark-parton model and the quark-gluon string model. To solve the muon
transport equation at large depths of homogeneous medium, a semi-analytical
method is used. The simple fitting formulas describing our numerical results
are given. Our analysis shows that, at depths up to 6-7 km w. e., essentially
all underground data on the muon intensity correlate with each other and with
predicted depth-intensity relation for conventional muons to within 10%.
However, the high-energy sea-level data as well as the data at large depths are
contradictory and cannot be quantitatively decribed by a single nuclear-cascade
model.Comment: 47 pages, REVTeX, 15 EPS figures included; recent experimental data
and references added, typos correcte
Results of the Test-Run of the Computer Software Model Support System for Managerial Decision Making
Considered is the experience of development of the decision support system (DSS) in the sphere of biological safety provision. Described are the objectives, functions, and architecture of DSS. Represented are the results of operational program-testing in the model territory (the Astrakhan region). Indicated is the effectiveness of DSS for information support of the control activity over internal and external biosafety hazards. Determined are the directions for further development of DSS
Protection from ultraviolet damage and photocarcinogenesis by vitamin d compounds
© Springer Nature Switzerland AG 2020. Exposure of skin cells to UV radiation results in DNA damage, which if inadequately repaired, may cause mutations. UV-induced DNA damage and reactive oxygen and nitrogen species also cause local and systemic suppression of the adaptive immune system. Together, these changes underpin the development of skin tumours. The hormone derived from vitamin D, calcitriol (1,25-dihydroxyvitamin D3) and other related compounds, working via the vitamin D receptor and at least in part through endoplasmic reticulum protein 57 (ERp57), reduce cyclobutane pyrimidine dimers and oxidative DNA damage in keratinocytes and other skin cell types after UV. Calcitriol and related compounds enhance DNA repair in keratinocytes, in part through decreased reactive oxygen species, increased p53 expression and/or activation, increased repair proteins and increased energy availability in the cell when calcitriol is present after UV exposure. There is mitochondrial damage in keratinocytes after UV. In the presence of calcitriol, but not vehicle, glycolysis is increased after UV, along with increased energy-conserving autophagy and changes consistent with enhanced mitophagy. Reduced DNA damage and reduced ROS/RNS should help reduce UV-induced immune suppression. Reduced UV immune suppression is observed after topical treatment with calcitriol and related compounds in hairless mice. These protective effects of calcitriol and related compounds presumably contribute to the observed reduction in skin tumour formation in mice after chronic exposure to UV followed by topical post-irradiation treatment with calcitriol and some, though not all, related compounds
THE USE OF GENETIC RESOURCES IN BREEDING OF VEGETABLE AND MELON CROPS
The analysis of the modern homeland assortment of vegetable crops is given. The donors of the most important traits and the accessions of vegetable and melon crops perspective for breeding from the VIR collection are shown. The short characteristic of the varieties is given