89 research outputs found
Study of the Iron State in Pharmaceutical Products Using Mössbauer Spectroscopy
This work is devoted to study of the iron state in iron-containing pharmaceuticals using Mössbauer spectroscopy. Obtained results showed useful application of Mössbauer spectroscopy for characterization of the iron state in various pharmaceutical products.The authors wish to thank Dr. I. N. Antsigin for useful comments and support. This work was supported by the Ministry of Science and Higher Education of the Russian Federation, project # FEUZ-2020-0060
TREATMENT OF HIRSCHSPRUNG DISEASE IN ADULTS
The article presents our own experience of treatment of Hirschsprung disease in adults
The optical identifcation of events with poorly defined locations: The case of the Fermi GBM GRB140801A
We report the early discovery of the optical afterglow of gamma-ray burst
(GRB) 140801A in the 137 deg 3- error-box of the Fermi Gamma-ray
Burst Monitor (GBM). MASTER is the only observatory that automatically react to
all Fermi alerts. GRB 140801A is one of the few GRBs whose optical counterpart
was discovered solely from its GBM localization. The optical afterglow of GRB
140801A was found by MASTER Global Robotic Net 53 sec after receiving the
alert, making it the fastest optical detection of a GRB from a GBM error-box.
Spectroscopy obtained with the 10.4-m Gran Telescopio Canarias and the 6-m BTA
of SAO RAS reveals a redshift of . We performed optical and
near-infrared photometry of GRB 140801A using different telescopes with
apertures ranging from 0.4-m to 10.4-m. GRB 140801A is a typical burst in many
ways. The rest-frame bolometric isotropic energy release and peak energy of the
burst is erg and
keV, respectively, which is consistent with the
Amati relation. The absence of a jet break in the optical light curve provides
a lower limit on the half-opening angle of the jet deg. The
observed is consistent with the limit derived from the
Ghirlanda relation. The joint Fermi GBM and Konus-Wind analysis shows that GRB
140801A could belong to the class of intermediate duration. The rapid detection
of the optical counterpart of GRB 140801A is especially important regarding the
upcoming experiments with large coordinate error-box areas.Comment: in press MNRAS, 201
Detection of tick-borne pathogens in wild birds and their ticks in Western Siberia and high level of their mismatch
Abstract: The Tomsk region located in the south of Western Siberia is one of the most high-risk areas for tick-borne diseases due to elevated incidence of tick-borne encephalitis and Lyme disease in humans. Wild birds may be considered as one of the reservoirs for tick-borne pathogens and hosts for infected ticks. A high mobility of wild birds leads to unpredictable possibilities for the dissemination of tick-borne pathogens into new geographical regions. The primary goal of this study was to evaluate the prevalence of tick-borne pathogens in wild birds and ticks that feed on them as well as to determine the role of different species of birds in maintaining the tickborne infectious foci. We analysed the samples of 443 wild birds (60 species) and 378 ticks belonging to the genus Ixodes Latraille, 1795 collected from the wild birds, for detecting occurrence of eight tick-borne pathogens, the namely tick-borne encephalitis virus (TBEV), West Nile virus (WNV), and species of Borrelia, Rickettsia, Ehrlichia, Anaplasma, Bartonella and Babesia Starcovici, 1893, using RT-PCR/or PCR and enzyme immunoassay. One or more tick-borne infection markers were detected in 43 species of birds. All markers were detected in samples collected from fieldfare Turdus pilaris Linnaeus, Blyth’s reed warbler Acrocephalus dumetorum Blyth, common redstart Phoenicurus phoenicurus (Linnaeus), and common chaffinch Fringilla coelebs Linnaeus. Although all pathogens have been identified in birds and ticks, we found that in the majority of cases (75.5%), there were mismatches of pathogens in birds and ticks collected from them. Wild birds and their ticks may play an extremely important role in the dissemination of tick-borne pathogens into different geographical regions
Photometry and Modeling of Type IIb Supernova 2017gpn
Observations of SN 2017gpn were performed using a CCD photometer of the Zeiss-1000 telescope (SAO RAS). In this work we present the photometry of 20 epochs of those observations. Based on the photometric data, the light curves of SN 2017gpn in B and R filters were obtained. The multicolor light curves were modeled numerically using the one-dimensional radiation hydrodynamical code STELLA. The question that SN 2017gpn lies well outside the host galaxy (NGC 1343) disk was discussed.Были выполнены наблюдения СН 2017gpn с помощью ПЗС-фотометра телескопа Цейсс-1000 (САО РАН) и проведена фотометрия 20 эпох наблюдений. На основе фотометрических данных были построены кривые блеска СН 2017gpn в B- и R-фильтрах. С помощью радиационного гидродинамического кода STELLA было проведено моделирование двухцветной кривой блеска и определены параметры пред-сверхновой звезды. Также мы изучили вопрос исключительного положения СН 2017gpn относительно центра родительской галактики NGC 1343.Работа выполнена при поддержке гранта РНФ 18-12-00522, а также программы развития МГУ «Выдающиеся научные школы МГУ: Физика звезд, релятивистских компактных объектов и галактик»
Transition from Fireball to Poynting-flux-dominated Outflow in Three-Episode GRB 160625B
The ejecta composition is an open question in gamma-ray bursts (GRB) physics.
Some GRBs possess a quasi-thermal spectral component in the time-resolved
spectral analysis, suggesting a hot fireball origin. Others show a featureless
non-thermal spectrum known as the "Band" function, consistent with a
synchrotron radiation origin and suggesting that the jet is
Poynting-flux-dominated at the central engine and likely in the emission region
as well. There are also bursts showing a sub-dominant thermal component and a
dominant synchrotron component suggesting a likely hybrid jet composition. Here
we report an extraordinarily bright GRB 160625B, simultaneously observed in
gamma-rays and optical wavelengths, whose prompt emission consists of three
isolated episodes separated by long quiescent intervals, with the durations of
each "sub-burst" being 0.8 s, 35 s, and 212 s, respectively. Its high
brightness (with isotropic peak luminosity L
erg/s) allows us to conduct detailed time-resolved spectral analysis in each
episode, from precursor to main burst and to extended emission. The spectral
properties of the first two sub-bursts are distinctly different, allowing us to
observe the transition from thermal to non-thermal radiation between
well-separated emission episodes within a single GRB. Such a transition is a
clear indication of the change of jet composition from a fireball to a
Poynting-flux-dominated jet.Comment: Revised version reflecting the referees' comments. 27 pages, 11
figures, 5 tables. The final edited version will appear in Nature Astronom
Transition from fireball to Poynting-flux-dominated outflow in the three-episode GRB 160625B
© 2017 The Author(s). The ejecta composition is an open question in gamma-ray burst (GRB) physics 1 . Some GRBs possess a quasi-thermal spectral component in the time-resolved spectral analysis 2, suggesting a hot fireball origin. Others show a featureless non-thermal spectrum known as the Band function 3-5, consistent with a synchrotron radiation origin 5,6 and suggesting that the jet is Poynting-flux dominated at the central engine and probably in the emission region as well 7,8 . There are also bursts showing a sub-dominant thermal component and a dominant synchrotron component 9, suggesting a probable hybrid jet composition 10 . Here, we report an extraordinarily bright GRB 160625B, simultaneously observed in gamma-ray and optical wavelengths, whose prompt emission consists of three isolated episodes separated by long quiescent intervals, with the durations of each sub-burst being approximately 0.8 s, 35 s and 212 s, respectively. Its high brightness (with isotropic peak luminosity L p,iso ≈ 4 × 1053 erg s-1) allows us to conduct detailed time-resolved spectral analysis in each episode, from precursor to main burst and to extended emission. The spectral properties of the first two sub-bursts are distinctly different, allowing us to observe the transition from thermal to non-thermal radiation between well-separated emission episodes within a single GRB. Such a transition is a clear indication of the change of jet composition from a fireball to a Poynting-flux-dominated jet
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