355 research outputs found

    Some questions of equivariant movability

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    In this paper the some questions of equivariant movability connected with substitution of acting group GG on closed subgroup HH and with transitions to spaces of HH-orbits and HH-fixed points spaces are investigated. In the special case the characterization of equivariant-movable GG-spaces is given.Comment: 12 page

    Movable categories

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    The notion of movability for metrizable compacts was introduced by K.Borsuk [1][1]. In this paper we define the notion of movable category and prove that the movability of a topological space XX coincides with the movability of a suitable category, which is generated by the topological space XX (i.e., the category WXW^X, defined by S.Mardesic)

    Some questions of equivariant movability

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    In this article some questions of equivariant movability, connected with the substitution of the acting group G on closed subgroup H and with transitions to spaces of H-orbits and H-fixed points spaces, are investigated. In a special case, the characterization of equivariantly movable G-spaces is given

    Movable categories

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    The notion of movability for metrizable compacta was introduced by K.Borsuk. In this paper we define the notion of a movable category and prove that the movability of a topological space X coincides with the movability of a suitable category, which is generated by the topological space X (i.e., the category X, defined by S.Mardesic)

    Efficient synthesis of novel benzo[b][1,8]naphthyridin-4(1H)-ones and pyrido[2,3-b]quinoxalin-4(1H)-ones from alkynones and primary amines

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    An efficient palladium-catalyzed cyclization of o-chlorohetaryl ynones with aliphatic and aromatic primary amines represents a simple access to a wide range of benzo[b][1,8]naphthyridin-4(1H)-one and pyrido[2,3-b]quinoxalin-4(1H)- one derivatives in good to excellent yields. © 2013 Elsevier Ltd. All rights reserved

    HYDRODISSECTION FOR PRESERVATION OF NEUROVASCULAR BUNDLE DURING RADICAL PROSTATECTOMY

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    Nerve-sparing radical prostatectomy is one of the high-tech operations in urology, and the challenge of the surgeon is not only to remove the prostate tumor, but also to provide a high quality of life. The fact that most questions devoted from patients in a conversation with the surgeon before the operation are devoted to this issue, shows the importance and relevance. At present, the diagnostic methods allow significantly more likely to detect early  prostate cancer, making finding and treatment of these patients more affordable and allows to apply this operation.Lately, it seems urgent to explore the possibility of water jet dissection in the field of urology, in particular, for nerve-sparing prostatectomy. Preservation of erectile function depends largely on the quality of separating the neurovascular bundle. Standard use of electrocautery is associated with damage to the neurovascular bundle.  When performing operations using water-jet mobilization of prostate the selective dissection of tissue is performed. This avoids injury of neurovascular bundle and further postoperative complications. The use of this technique may allow the surgeon to provide a more accurate mobilization prostate and selectively controlled intersection vessels heading to the prostate from the neurovascular bundle, reduce intraoperative blood loss,  maintaining continence, erectile function.This literature review is considered by the experience of using nerve-sparing radical prostatectomy using a water-jet dissector, estimated intraoperative parameters using this method.However, we have the lack of extensive research capabilities of this technique when performing nerve-preserving radical prostatectomy, that does not allow to make a comprehensive presentation on the benefits of this technique and its effects on erectile function and quality of urination, further study of this issue in such a difficult category of patients

    Near-threshold Photoproduction of Phi Mesons from Deuterium

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    We report the first measurement of the differential cross section on ϕ\phi-meson photoproduction from deuterium near the production threshold for a proton using the CLAS detector and a tagged-photon beam in Hall B at Jefferson Lab. The measurement was carried out by a triple coincidence detection of a proton, K+K^+ and KK^- near the theoretical production threshold of 1.57 GeV. The extracted differential cross sections dσdt\frac{d\sigma}{dt} for the initial photon energy from 1.65-1.75 GeV are consistent with predictions based on a quasifree mechanism. This experiment establishes a baseline for a future experimental search for an exotic ϕ\phi-N bound state from heavier nuclear targets utilizing subthreshold/near-threshold production of ϕ\phi mesons

    The Heavy Photon Search test detector

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    The Heavy Photon Search (HPS), an experiment to search for a hidden sector photon in fixed target electroproduction, is preparing for installation at the Thomas Jefferson National Accelerator Facility (JLab) in the Fall of 2014. As the first stage of this project, the HPS Test Run apparatus was constructed and operated in 2012 to demonstrate the experiment׳s technical feasibility and to confirm that the trigger rates and occupancies are as expected. This paper describes the HPS Test Run apparatus and readout electronics and its performance. In this setting, a heavy photon can be identified as a narrow peak in the e+e− invariant mass spectrum above the trident background or as a narrow invariant mass peak with a decay vertex displaced from the production target, so charged particle tracking and vertexing are needed for its detection. In the HPS Test Run, charged particles are measured with a compact forward silicon microstrip tracker inside a dipole magnet. Electromagnetic showers are detected in a PbW04 crystal calorimeter situated behind the magnet, and are used to trigger the experiment and identify electrons and positrons. Both detectors are placed close to the beam line and split top-bottom. This arrangement provides sensitivity to low-mass heavy photons, allows clear passage of the unscattered beam, and avoids the spray of degraded electrons coming from the target. The discrimination between prompt and displaced e+e− pairs requires the first layer of silicon sensors be placed only 10 cm downstream of the target. The expected signal is small, and the trident background huge, so the experiment requires very large statistics. Accordingly, the HPS Test Run utilizes high-rate readout and data acquisition electronics and a fast trigger to exploit the essentially 100% duty cycle of the CEBAF accelerator at JLab
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