Hard X-ray emission of Sco X-1

We study hard X-ray emission of the brightest accreting neutron star Sco X-1 with INTEGRAL observatory. Up to now INTEGRAL have collected ~4 Msec of deadtime corrected exposure on this source. We show that hard X-ray tail in time average spectrum of Sco X-1 has a power law shape without cutoff up to energies ~200-300 keV. An absence of the high energy cutoff does not agree with the predictions of a model, in which the tail is formed as a result of Comptonization of soft seed photons on bulk motion of matter near the compact object. The amplitude of the tail varies with time with factor more than ten with the faintest tail at the top of the so-called flaring branch of its color-color diagram. We show that the minimal amplitude of the power law tail is recorded when the component, corresponding to the innermost part of optically thick accretion disk, disappears from the emission spectrum. Therefore we show that the presence of the hard X-ray tail may be related with the existence of the inner part of the optically thick disk. We estimate cooling time for these energetic electrons and show that they can not be thermal. We propose that the hard X-ray tail emission originates as a Compton upscattering of soft seed photons on electrons, which might have initial non-thermal distribution.Comment: 9 pages, 7 figures, Accepted for publication in MNRA

Population of persistent high mass X-ray binaries in the Milky Way

We present results of the study of persistent high mass X-ray binaries (HMXBs) in the Milky Way, obtained from the deep INTEGRAL Galactic plane survey. This survey provides us a new insight into the population of high mass X-ray binaries because almost half of the whole sample consists of sources discovered with INTEGRAL. It is demonstrated for the first time that the majority of persistent HMXBs have supergiant companions and their luminosity function steepens somewhere around ~2x10^{36} erg/s. We show that the spatial density distribution of HMXBs correlates well with the star formation rate distribution in the Galaxy. The vertical distribution of HMXBs has a scale-height h~85 pc, that is somewhat larger than the distribution of young stars in the Galaxy. We propose a simple toy model, which adequately describes general properties of HMXBs in which neutron stars accrete a matter from the wind of the its companion (wind-fed NS-HMXBs population). Using the elaborated model we argue that a flaring activity of so-called supergiant fast X-ray transients, the recently recognized sub-sample of HMXBs, is likely related with the magnetic arrest of their accretion.Comment: 17 pages, 12 figures, accepted for publicatiopn in MNRA

Deformation indicators of metacarpal bones fracture fixation

Досліджено функціональну надійність засобів фіксатор-кістка при різних типах переломів п’ясних кісток в залежності від типу фіксатора та його розташування. Вивчені характеристики жорсткості систем фіксації переломів з титановими мініпластинами, був проведений аналіз оперативного лікування хворих з переломами п’ясних кісток, при якому застосовувався металоостеосинтез шпицями та стрижневий апарат зовнішньої фіксації, при статичних та циклічних режимах дії зовнішніх навантажень. При передачі стискаючого зусилля на відламок тип фіксуючих засобів суттєво впливає на деформації системи остеосинтезу при всіх рівнях навантаження; за більшістю виміряних характеристик перевагу мають стрижневі апарати зовнішньої фіксації та титанові мініпластини різних конструкцій.Functional reliability of fixative-bone means was studied for various types of metacarpal fractures depending on the type of fixator and its location. The stiffness characteristics of fracture fixation systems with titanium miniplates were studied, an analysis was performed of the surgical treatment of patients with metacarpal fractures, in which osteosynthesis with needles and external fixation rod apparatus was used, with static and cyclic modes of action of external loads. When transferring a compressive force to a fragment, the type of fixing means significantly influences the deformation of the osteosynthesis system at all levels of stress; for the most of the measured characteristics, rod devices with external fixation and titanium miniplates of various designs are preferable.В статье исследована функциональная надежность средств фиксатор-кость при разных типах переломов пястных костей в зависимости от типа фиксатора и его расположения. Изучены характеристики жесткости систем фиксации переломов с титановыми минипластинами, был проведен анализ оперативного лечения больных с переломами пястных костей, при котором применялся металоостеосинтез спицами и стержневой аппарат внешней фиксации, при статичных и циклических режимах действия внешних нагрузок. При передаче сжимающего усилия на обломок тип фиксирующих средств существенно влияет на деформации системы остеосинтеза при всех уровнях нагрузки; за большинством измеренных характеристик преимущество имеют стержневые аппараты внешней фиксации и титановые минипластины разных конструкций

Expanding hot flow in the black hole binary SWIFT J1753.5-0127: evidence from optical timing

We describe the evolution of optical and X-ray temporal characteristics during the outburst decline of the black hole X-ray binary SWIFT J1753.5-0127. The optical/X-ray cross-correlation function demonstrates a single positive correlation at the outburst peak, then it has multiple dips and peaks during the decline stage, which are then replaced by the precognition dip plus peak structure in the outburst tail. Power spectral densities and phase lags show a complex evolution, revealing the presence of intrinsically connected optical and X-ray quasi-periodic oscillations. For the first time, we quantitatively explain the evolution of these timing properties during the entire outburst within one model, the essence of which is the expansion of the hot accretion flow towards the tail of the outburst. The pivoting of the spectrum produced by synchrotron Comptonization in the hot flow is responsible for the appearance of the anti-correlation with the X-rays and for the optical quasi-periodic oscillations. Our model reproduces well the cross-correlation and phase lag spectrum during the decline stage, which could not be understood with any model proposed before.Comment: 13 pages, 11 figures, MNRAS submitte

A study of cell membranes in nasal epithelial cells from patients with chronic rhinosinusitis with nasal polyps by means of a fluorescent probe

Aim. To assess the state of membranes in nasal epithelial cells obtained from the patients with chronic rhinosinusitis with nasal polyps (CRSwNP) with the help of the fluorescent probe 2-(2ʹ-ОН-phenyl)-5-phenyl-1,3-oxazole. Methods. The state of membrane phospholipid bilayer in suspensions of nasal epithelial cells isolated from ten patients with CRSwNP was evaluated using the fluorescent probe 2-(2ʹ-ОН-phenyl)-5-phenyl-1,3-oxazole that reacts on the physico-chemical properties of its microenvironment. Changes in fluorescence spectra were determined using a Thermo Scientific Lumina fluorescence spectrometer (Thermo Fisher Scientific) 1 hour after the addition of the probe to nasal epithelial cell suspensions. Results. CRSwNP was found to be associated with a higher rate of nasal epithelial cell membrane hydration in the region of phospholipid glycerol moiety, carbonyl groups and aliphatic chains of fatty acids attached to the carbonyl groups. Conclusion. Our findings suggest that CRSwNP is accompanied by the elevated hydration rate of the most polar region, namely polar heads of phospholipids of nasal epithelial cell membranes