4,964 research outputs found
Detection of Giant Radio Pulses from the Pulsar PSR B0656+14
Giant pulses (GPs) have been detected from the pulsar PSR B0656+14. A pulse
that is more intense than the average pulse by a factor of 120 is encountered
approximately once in 3000 observed periods of the pulsar. The peak flux
density of the strongest pulse, 120 Jy, is a factor of 630 higher than that of
the average pulse. The GP energy exceeds the energy of the average pulse by up
to a factor of 110, which is comparable to that for other known pulsars with
GPs, including the Crab pulsar and the millisecond pulsar PSR B1937+21. The
giant pulses are a factor of 6 narrower than the average pulse and are
clustered at the head of the average pulse. PSR B0656+14 along with PSR
B0031-07, PSR B1112+50, and PSR J1752+2359 belong to a group of pulsars that
differ from previously known ones in which GPs have been detected without any
extremely strong magnetic field on the light cylinder.Comment: 10 pages, 3 figures, 1 table; originally published in Russian in
Pis'ma Astron. Zh., 2006, v.32, 650; translated by George Rudnitskii; the
English version will be appear in Astronomy Letter
Analysis of the placental tissue transcriptome of normal and preeclampsia complicated pregnancies
Preeclampsia is one of the most severe gestational complications which is one of the leading causes of maternal and perinatal morbidity and mortality. A growth in the incidence of severe and combined forms of the pathology has been observed in recent years. According to modern concepts, inadequate cytotrophoblast invasion into the spiral arteries of the uterus and development of the ischemia-reperfusion syndrome in the placental tissue play the leading role in the development of preeclampsia, which is characterized by multipleorgan failure. In this regard, our work was aimed at studying the patterns of placental tissue transcriptome that are specific to females with PE and with physiological pregnancy, as well as identifying the potential promising biomarkers and molecular mechanisms of this pathology. We have identified 63 genes whose expression proved to differ significantly in the placental tissue of females with PE and with physiological pregnancy. A cluster of differentially expressed genes (DEG) whose expression level is increased in patients with preeclampsia includes not only the known candidate genes that have been identified in many other genome-wide studies (e.g., LEP, BHLHB2, SIGLEC6, RDH13, BCL6), but also new genes (ANKRD37, SYDE1, CYBA, ITGB2, etc.), which can be considered as new biological markers of preeclampsia and are of further interest. The results of a functional annotation of DEG show that the development of preeclampsia may be related to a stress response, immune processes, the regulation of cell-cell interactions, intracellular signaling cascades, etc. In addition, the features of the differential gene expression depending on preeclampsia severity were revealed. We have found evidence of the important role of the molecular mechanisms responsible for the failure of immunological tolerance and initiation of the pro-inflammatory cascade in the development of severe preeclampsia. The results obtained elaborate the concept of the pathophysiology of preeclampsia and contain the information necessary to work out measures for targeted therapy of this disease.
Three-body correlations in direct reactions: Example of Be populated in reaction
The Be continuum states were populated in the charge-exchange reaction
H(Li,Be) collecting very high statistics data ( events) on the three-body ++ correlations. The
Be excitation energy region below MeV is considered, where the
data are dominated by contributions from the and states. It is
demonstrated how the high-statistics few-body correlation data can be used to
extract detailed information on the reaction mechanism. Such a derivation is
based on the fact that highly spin-aligned states are typically populated in
the direct reactions.Comment: submitted to Physical Review
Anode off-gas recirculation ejector modelling at various operation modes
The article includes methods for calculation of the anode off-gas equilibrium chemical composition, anode off-gas recirculation ratio at which the carbon deposition fails to occur in the reformer and fuel cell anode channel and the ejector’s entrainment ratio for the SOFC power unit with anode off-gas recirculation at various operation modes.В статье приведены методики расчета состава уходящего анодного газа, степени рециркуляции, обеспечивающей протекание реакций риформинга с отсутствием сажеобразования, а также коэффициента инжекции эжектора в схеме с рециркуляцией анодных газов для различных режимов работы установки
Using the inverse solver "inverse" in PAM-STAMP 2G to assess the formability of a part
This article discusses the possibility of using a finite-element-based inverse design method to evaluate a technology for making parts by cold sheet stamping. It examines the process of reengineering in the software suite PAM-STAMP. The results that are obtained provide information on the development of the product and different pre-computed fields: stress-strain state, thickness reductions, defects, etc. © 2013 Springer Science+Business Media New York
Synthesis and Cytotoxic Effect of 1-Aryl-Substituted-6-Imino-2,7-Dioxabicyclo[3.2.1]Octane-4,4,5-Tricarbonitriles
The work was carried out within the framework of scholarship SP-127.2016.4 from the President of the Russian Federation for young scientists and graduate students
Giant Pulses -- the Main Component of the Radio Emission of the Crab Pulsar
The paper presents an analysis of dual-polarization observations of the Crab
pulsar obtained on the 64-m Kalyazin radio telescope at 600 MHz with a time
resolution of 250 ns. A lower limit for the intensities of giant pulses is
estimated by assuming that the pulsar radio emission in the main pulse and
interpulse consists entirely of giant radio pulses; this yields estimates of
100 Jy and 35 Jy for the peak flux densities of giant pulses arising in the
main pulse and interpulse, respectively. This assumes that the normal radio
emission of the pulse occurs in the precursor pulse. In this case, the
longitudes of the giant radio pulses relative to the profile of the normal
radio emission turn out to be the same for the Crab pulsar and the millisecond
pulsar B1937+21, namely, the giant pulses arise at the trailing edge of the
profile of the normal radio emission. Analysis of the distribution of the
degree of circular polarization for the giant pulses suggests that they can
consist of a random mixture of nanopulses with 100% circular polarization of
either sign, with, on average, hundreds of such nanopulses within a single
giant pulse.Comment: 13 pages, 6 figures (originally published in Russian in
Astronomicheskii Zhurnal, 2006, vol. 83, No. 1, pp. 62-69) translated by
Denise Gabuzd
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