696 research outputs found

    Clinical-anatomical grounding for pancreatoduodenectomy with preservation of the lesser pancreas

    Get PDF
    The article presents clinical-anatomical grounding and the first clinical experience of pancreatoduodenectomy with preservation of the lesser pancreas. Implementation of this technique is feasible due to relative anatomical and functional isolation of the lesser pancreas. For the first time in Russia, in the Clinic of Hospital Surgery of Siberian State Medical University pancreatoduodenectomy surgery with preservation of the lesser pancreas was successfully performed in female patient with cancer of the head of pancreas. Pancreatoduodenectomy with preservation of the lesser pancreas enables to augment surgical radicality and to achieve endocrine function of the pancreas at the level requiring relatively low doses of insulin therapy if any. This approach increases the length of life in this category of patients and preserves the quality of life

    Tectonic history of the Kolyvan–Tomsk folded zone (KTFZ), Russia : insight from zircon U / Pb geochronology and Nd isotopes

    Get PDF
    The Kolyvan-Tomsk folded zone (KTFZ) represents part of the Central Asian Orogenic Belt (CAOB). The KTFZ is mainly composed of detrital Late Palaeozoic sedimentary deposits, with minor intrusions. Detrital zircon geochronology on the Upper Devonian to Lower Permian sedimentary sequences of the KTFZ and the associated Gorlovo foreland basin yields four age peaks, reflecting the magmatic events in the source terranes. These events consist of (a) a minor Neoproterozoic peak (0.9-0.7 Ga), (b) a significant Early Palaeozoic peak (550-460 Ma), with a maximum at 500 Ma, and two well-defined Late Palaeozoic peaks during (c) the Middle-Late Devonian (385-360 Ma) and (d) the Carboniferous-Early Permian (360-280 Ma), with a maximum at 320 Ma. Older zircons (>1 Ga) are quite rare in the sampled sedimentary sequences. Slightly negative epsilon Nd values and associated relatively young Nd model ages were obtained (epsilon Nd(T) = -0.78, T (DM) ~1.1 Ga for Upper Devonian sandstones, epsilon Nd(T) = -1.1, T (DM) ~1.1 Ga for Lower Permian sandstones), suggesting only minor contribution of ancient continental crust to the main sedimentary units of the KTFZ. All intrusive and volcaniclastic rocks on the contrary are characterized by high positive epsilon Nd(T) values in the range of 3.78-6.86 and a Late Precambrian model age (T (DM) = 581-916 Ma), which corroborates its juvenile nature and an important depleted mantle component in their source. The oldest unit of the KTFZ, the Bugotak volcanic complex formed at the Givetian-Early Frasnian transition, at about 380 Ma. Upper Devonian detrital deposits of the KTFZ were formed in the Early Palaeozoic accretion belt of the Siberian continent and specifically in a passive continental margin environment. Deposits of the Gorlovo foreland basin, adjoining the KTFZ, were accumulated as a result of erosion of the Carboniferous-Early Permian volcanic rocks, which are now buried under the Meso-Cenozoic sedimentary cover of the West Siberian Basin. The magmatic events, recorded in the KTFZ zircon data, correspond to the most significant magmatic stages that affected the western part of the CAOB as a whole

    Search for electron antineutrino interactions with the Borexino Counting Test Facility at Gran Sasso

    Full text link
    Electron antineutrino interactions above the inverse beta decay energy of protons (E_\bar{\nu}_e>1.8) where looked for with the Borexino Counting Test Facility (CTF). One candidate event survived after rejection of background, which included muon-induced neutrons and random coincidences. An upper limit on the solar νˉe\bar{\nu}_{e} flux, assumed having the 8^8B solar neutrino energy spectrum, of 1.1×105\times10^{5} cm2^{-2}~s1^{-1} (90% C.L.) was set with a 7.8 ton ×\times year exposure. This upper limit corresponds to a solar neutrino transition probability, νeνˉe\nu_{e} \to \bar{\nu}_{e}, of 0.02 (90% C.L.). Predictions for antineutrino detection with Borexino, including geoneutrinos, are discussed on the basis of background measurements performed with the CTF.Comment: 10 pages, 9 figures, 5 table

    Tunka-Rex Virtual Observatory

    Get PDF
    Tunka-Rex (Tunka Radio Extension) was a detector for ultra-high energy cosmic rays measuring radio emission for air showers in the frequency band of 30-80 MHz, operating in 2010s. It provided an experimental proof that sparse radio arrays can be a cost-effective technique to measure the depth of shower maximum with resolutions competitive to optical detectors. After the decommissioning of Tunka-Rex, as last phase of its lifecycle and following the FAIR (Findability — Accessibility — Interoperability — Reuse) principles, we publish the data and software under free licenses in the frame of the TRVO (Tunka-Rex Virtual Observatory), which is hosted at KIT under the partnership with the KCDC and GRADLCI projects. We present the main features of TRVO, its interface and give an overview of projects, which benefit from its open software and data

    Prospects for K+π+ννˉK^+ \to \pi^+ \nu \bar{ \nu } at CERN in NA62

    Full text link
    The NA62 experiment will begin taking data in 2015. Its primary purpose is a 10% measurement of the branching ratio of the ultrarare kaon decay K+π+ννˉK^+ \to \pi^+ \nu \bar{ \nu }, using the decay in flight of kaons in an unseparated beam with momentum 75 GeV/c.The detector and analysis technique are described here.Comment: 8 pages for proceedings of 50 Years of CP

    Reconstruction of sub-threshold events of cosmic-ray radio detectors using an autoencoder

    Get PDF
    Radio detection of air showers produced by ultra-high energy cosmic rays is a cost-effective technique for the next generation of sparse arrays. The performance of this technique strongly depends on the environmental background, which has different constituents, namely anthropogenic radio frequency interferences, synchrotron galactic radiation and others. These components have recognizable features, which can help for background suppression. A powerful method for handling this is the application of convolution neural networks with a specific architecture called autoencoder. By suppressing unwanted signatures, the autoencoder keeps the signal-like ones. We have successfully developed and trained an autoencoder, which is now applied to the data from Tunka-Rex. We show the procedures of the training and optimization of the network including benchmarks of different architectures. Using the autoencoder, we improved the standard analysis of Tunka-Rex in order to lower the threshold of the detection. This enables the reconstructing of sub-threshold events with energies lower than 0.1 EeV with satisfactory angular and energy resolutions

    Directional Sensitivity of the NEWSdm Experiment to Cosmic Ray Boosted Dark Matter

    Full text link
    We present a study of a directional search for Dark Matter boosted forward when scattered by cosmic-ray nuclei, using a module of the NEWSdm experiment. The boosted Dark Matter flux at the edge of the Earth's atmosphere is expected to be pointing to the Galactic Center, with a flux 15 to 20 times larger than in the transverse direction. The module of the NEWSdm experiment consists of a 10 kg stack of Nano Imaging Trackers, i.e.~newly developed nuclear emulsions with AgBr crystal sizes down to a few tens of nanometers. The module is installed on an equatorial telescope. The relatively long recoil tracks induced by boosted Dark Matter, combined with the nanometric granularity of the emulsion, result in an extremely low background. This makes an installation at the INFN Gran Sasso laboratory, both on the surface and underground, viable. A comparison between the two locations is made. The angular distribution of nuclear recoils induced by boosted Dark Matter in the emulsion films at the surface laboratory is expected to show an excess with a factor of 3.5 in the direction of the Galactic Center. This excess allows for a Dark Matter search with directional sensitivity. The surface laboratory configuration prevents the deterioration of the signal in the rock overburden and it emerges as the most powerful approach for a directional observation of boosted Dark Matter with high sensitivity. We show that, with this approach, a 10 kg module of the NEWSdm experiment exposed for one year at the Gran Sasso surface laboratory can probe Dark Matter masses between 1 keV/c2^2 and 1 GeV/c2^2 and cross-section values down to 103010^{-30}~cm2^2 with a directional sensitive search.Comment: 15 pages, 14 figures, updated references, clarified discussion in intro section. Submitted to JCA

    The Borexino detector at the Laboratori Nazionali del Gran Sasso

    Full text link
    Borexino, a large volume detector for low energy neutrino spectroscopy, is currently running underground at the Laboratori Nazionali del Gran Sasso, Italy. The main goal of the experiment is the real-time measurement of sub MeV solar neutrinos, and particularly of the mono energetic (862 keV) Be7 electron capture neutrinos, via neutrino-electron scattering in an ultra-pure liquid scintillator. This paper is mostly devoted to the description of the detector structure, the photomultipliers, the electronics, and the trigger and calibration systems. The real performance of the detector, which always meets, and sometimes exceeds, design expectations, is also shown. Some important aspects of the Borexino project, i.e. the fluid handling plants, the purification techniques and the filling procedures, are not covered in this paper and are, or will be, published elsewhere (see Introduction and Bibliography).Comment: 37 pages, 43 figures, to be submitted to NI
    corecore