СРАВНИТЕЛЬНЫЙ АНАЛИЗ СТЕПЕНИ ВАСКУЛЯРИЗАЦИИ ГЕПАТОЦЕЛЛЮЛЯРНОГО РАКА И ОЧАГОВОЙ УЗЛОВОЙ ГИПЕРПЛАЗИИ ПЕЧЕНИ ПО ДАННЫМ КОМПЬЮТЕРНО-ТОМОГРАФИЧЕСКОГО И МОРФОЛОГИЧЕСКОГО ИССЛЕДОВАНИЙ

A comparative analysis of vascularization degree of hepatocellular carcinoma and focal nodular hyperplasia of the liver according to the multislice computed tomography and histological study of tissue is presented. It was established that computed tomography with bolus contrast enhancement allows to study the characteristics of blood supply of the liver and focal formations. Frequently only the use of this method helps to evaluate specific morphological structure of tumors - hepatocellular carcinoma or focal nodular hyperplasia. As an additional differential diagnostic feature is recommended to increase the density determination of tissue formation in the arterial phase computed tomography study. The maximum of vascularization by computed tomography and immunohistochemistry (with antibodies CD34) are installed in a tissue of highly differentiated hepatocellular carcinoma.Проведен сравнительный анализ степени васкуляризации гепатоцеллюлярного рака и очаговой узловой гиперплазии печени по данным мультиспиральной компьютерной томографии и гистологического исследования ткани образований. Установлено, что использование компьютерной томографии с болюсным контрастным усилением позволяет изучить особенности кровоснабжения очаговых образований печени и часто только по данным этого исследования решить вопрос о конкретной морфологической структуре новообразования – гепатоцеллюлярный рак или очаговая узловая гиперплазия. В качестве дополнительного дифференциально-диагностического признака рекомендуется определение прироста плотности ткани образования в артериальную фазу компьютерно-томографического исследования. Максимальные значения степени васкуляризации по данным компьютерной томографии и иммуногистохимического исследования (с антителами CD34) установлены в ткани высокодифференцированного гепатоцеллюлярного рака.

ГОЛОВНІ НАПРЯМИ ТА РЕЗУЛЬТАТИ МОДЕРНІЗАЦІЇ СТРАТИГРАФІЧНИХ СХЕМ КАРБОНУ ТА ПЕРМІ УКРАЇНИ (1993-2014 рр.)

 The main distinctions of the new modernized Carboniferous and Permian Stratigraphic Charts for the different regions of Ukraine from the Charts of 1993 year are shown and partly are illustrated. Наведені та частково проілюстровані головні відміни модернізованих стратиграфічних схем карбону та пермі різних регіонів і субрегіонів України від схем, затверджених РМСК України у 1993 р. 

An Ultrahigh-energy γ\gamma-ray Bubble Powered by a Super PeVatron

International audienceWe report the detection of a $\gamma$-ray bubble spanning at least 100$\rm deg^2$ in ultra high energy (UHE) up to a few PeV in the direction of the star-forming region Cygnus X, implying the presence Super PeVatron(s) accelerating protons to at least 10 PeV. A log-parabola form with the photon index $\Gamma (E) = (2.71 \pm 0.02) + (0.11 \pm 0.02) \times \log_{10} (E/10 \ {\rm TeV})$ is found fitting the gamma-ray energy spectrum of the bubble well. UHE sources, `hot spots' correlated with very massive molecular clouds, and a quasi-spherical amorphous $\gamma$-ray emitter with a sharp central brightening are observed in the bubble. In the core of $\sim 0.5^{\circ}$, spatially associating with a region containing massive OB association (Cygnus OB2) and a microquasar (Cygnus X-3), as well as previously reported multi-TeV sources, an enhanced concentration of UHE $\gamma$-rays are observed with 2 photons at energies above 1 PeV. The general feature of the bubble, the morphology and the energy spectrum, are reasonably reproduced by the assumption of a particle accelerator in the core, continuously injecting protons into the ambient medium

Measurement of ultra-high-energy diffuse gamma-ray emission of the Galactic plane from 10 TeV to 1 PeV with LHAASO-KM2A

International audienceThe diffuse Galactic $\gamma$-ray emission, mainly produced via interactions between cosmic rays and the diffuse interstellar medium, is a very important probe of the distribution, propagation, and interaction of cosmic rays in the Milky Way. In this work we report the measurements of diffuse $\gamma$-rays from the Galactic plane between 10 TeV and 1 PeV energies, with the square kilometer array of the Large High Altitude Air Shower Observatory (LHAASO). Diffuse emissions from the inner ($15^{\circ}10$~TeV). The energy spectrum in the inner Galaxy regions can be described by a power-law function with an index of $-2.99\pm0.04$, which is different from the curved spectrum as expected from hadronic interactions between locally measured cosmic rays and the line-of-sight integrated gas content. Furthermore, the measured flux is higher by a factor of $\sim3$ than the prediction. A similar spectrum with an index of $-2.99\pm0.07$ is found in the outer Galaxy region, and the absolute flux for $10\lesssim E\lesssim60$ TeV is again higher than the prediction for hadronic cosmic ray interactions. The latitude distributions of the diffuse emission are consistent with the gas distribution, while the longitude distributions show slight deviation from the gas distribution. The LHAASO measurements imply that either additional emission sources exist or cosmic ray intensities have spatial variations

LHAASO-KM2A detector simulation using Geant4

International audienceKM2A is one of the main sub-arrays of LHAASO, working on gamma ray astronomy and cosmic ray physics at energies above 10 TeV. Detector simulation is the important foundation for estimating detector performance and data analysis. It is a big challenge to simulate the KM2A detector in the framework of Geant4 due to the need to track numerous photons from a large number of detector units (>6000) with large altitude difference (30 m) and huge coverage (1.3 km^2). In this paper, the design of the KM2A simulation code G4KM2A based on Geant4 is introduced. The process of G4KM2A is optimized mainly in memory consumption to avoid memory overffow. Some simpliffcations are used to signiffcantly speed up the execution of G4KM2A. The running time is reduced by at least 30 times compared to full detector simulation. The particle distributions and the core/angle resolution comparison between simulation and experimental data of the full KM2A array are also presented, which show good agreement

Constraints on Ultra Heavy Dark Matter Properties from Dwarf Spheroidal Galaxies with LHAASO Observations

International audienceIn this work we try to search for signals generated by ultra-heavy dark matter at the Large High Altitude Air Shower Observatory (LHAASO) data. We look for possible gamma-ray by dark matter annihilation or decay from 16 dwarf spheroidal galaxies in the field of view of LHAASO. Dwarf spheroidal galaxies are among the most promising targets for indirect detection of dark matter which have low fluxes of astrophysical $\gamma$-ray background while large amount of dark matter. By analyzing more than 700 days observational data at LHAASO, no significant dark matter signal from 1 TeV to 1 EeV is detected. Accordingly we derive the most stringent constraints on the ultra-heavy dark matter annihilation cross-section up to EeV. The constraints on the lifetime of dark matter in decay mode are also derived

Pointing calibration of LHAASO-WFCTA telescopes using bright stars

International audienceOne of the main scientific objectives of the Large High Altitude Air Shower Observatory (LHAASO) is to perform accurate measurements of the energy spectra for different cosmic ray masses, from a few TeV to 100 PeV. As one of the main sub-arrays of LHAASO, the Wide Field-of-View Cherenkov Telescope Array (WFCTA), which consists of 18 telescopes, can help in achieving this goal. The pointing accuracy of each telescope is crucial for reconstructing energy and determining mass-sensitive parameters. In this study, a method for absolute pointing calibration using ultraviolet bright stars was established. The proposed method can achieve a pointing accuracy of approximately 0.02° by using more than five stars. When more stars are used in the telescope’s field of view, the accuracy of the pointing calibration can be improved, e.g, a pointing accuracy of 0.01° can be achieved when using more than 15 stars. A high-precision inclinometer with a monitor resolution of 0.003° was installed on the camera to monitor the zenith direction of the telescope at every second. After calibration using bright stars, the absolute pointing accuracy of the inclinometer was 0.02°. •Method for absolute pointing calibration using ultraviolet bright stars established.•A pointing accuracy of ∼0.02°can be achieved using more than five stars.•A pointing accuracy of 0.01°can be achieved when using more than 15 stars•Accuracy of the pointing calibration increases with number of bright stars

An Ultrahigh-energy γ\gamma-ray Bubble Powered by a Super PeVatron

International audienceWe report the detection of a $\gamma$-ray bubble spanning at least 100$\rm deg^2$ in ultra high energy (UHE) up to a few PeV in the direction of the star-forming region Cygnus X, implying the presence Super PeVatron(s) accelerating protons to at least 10 PeV. A log-parabola form with the photon index $\Gamma (E) = (2.71 \pm 0.02) + (0.11 \pm 0.02) \times \log_{10} (E/10 \ {\rm TeV})$ is found fitting the gamma-ray energy spectrum of the bubble well. UHE sources, `hot spots' correlated with very massive molecular clouds, and a quasi-spherical amorphous $\gamma$-ray emitter with a sharp central brightening are observed in the bubble. In the core of $\sim 0.5^{\circ}$, spatially associating with a region containing massive OB association (Cygnus OB2) and a microquasar (Cygnus X-3), as well as previously reported multi-TeV sources, an enhanced concentration of UHE $\gamma$-rays are observed with 2 photons at energies above 1 PeV. The general feature of the bubble, the morphology and the energy spectrum, are reasonably reproduced by the assumption of a particle accelerator in the core, continuously injecting protons into the ambient medium

Constraints on Ultra Heavy Dark Matter Properties from Dwarf Spheroidal Galaxies with LHAASO Observations

International audienceIn this work we try to search for signals generated by ultra-heavy dark matter at the Large High Altitude Air Shower Observatory (LHAASO) data. We look for possible gamma-ray by dark matter annihilation or decay from 16 dwarf spheroidal galaxies in the field of view of LHAASO. Dwarf spheroidal galaxies are among the most promising targets for indirect detection of dark matter which have low fluxes of astrophysical $\gamma$-ray background while large amount of dark matter. By analyzing more than 700 days observational data at LHAASO, no significant dark matter signal from 1 TeV to 1 EeV is detected. Accordingly we derive the most stringent constraints on the ultra-heavy dark matter annihilation cross-section up to EeV. The constraints on the lifetime of dark matter in decay mode are also derived