106 research outputs found
Comparison of open femoral exposure and percutaneous access in endovascular reconstruction of the thoracic aorta: a two-center retrospective study
Aim. To analyze the efficacy and safety of the percutaneous transfemoral puncture technique for TEVAR (thoracis endovascular aortic repair).Material and methods. The retrospective study included 89 patients with aortic pathologies, for whom endovascular repair was performed: 51 patients (57%) with aortic dissection (type I DeBakey — 30 cases (58,8%) and type III — 21 (41,2%)), 38 (43%) patients with aortic aneurism. 82% of patients were male, the median age was 57 years (minimum age 17 years, maximum age 75 years). All patients were divided into two groups: in the first group (48 patients) endovascular aortic repair was performed under endotracheal anesthesia with open femoral exposure of the common femoral artery (CFA), in the second group (41 patients) — by percutaneous puncture method under local anesthesia. Technical and clinical aspects of procedures were analyzed.Results. Technical success of endovascular repair was achieved in 100% cases in both groups. The duration of the operation in the group with percutaneous access was statically significantly shorter (120 (94-150) minutes vs 87(60-120) minutes, p=0,001). Also, the time spent by patients in the intensive care unit and the period of hospitalization (18 (14-22) hours versus 1 (0-3) hours, p=0,001; 5 (4-6) days versus 4 (3-5) days, p=0,03) was shorter. In the open access group 2 (4,2%) patients developed access-related complications - acute thrombosis of the common femoral artery and hematoma of the postoperative wound, which required additional surgical aid - thrombectomy from the CFA, the second patient had evacuation of the hematoma of the postoperative wound. Cite-related complications in the second group were not observed. No major complications including neurological deficits and hospital mortality were observed in both groups.Conclusions. Thoracic endovascular aortic repair (TEVAR) using percutaneous access under local anesthesia in stable patients has proven to be safe and effective. The operation time is significantly reduced and this approach in most cases eliminates the need for the patient to stay in the intensive care unit in the early postoperative period. Possibility of early mobilization of the patient appears with reducing of the duration of hospitalization
Space charge and electron clouds issues
We present here the relevant space charge issues for long-term beam storage. The impact on the choice of the working point along with the prediction of the beam loss is discussed for the example of the SIS100. We present a first estimate on the effect of self consistency and discuss the equivalence of space charge, and electron clouds induced ”quasi” incoherent effect
Localized charged states and phase separation near second order phase transition
Localized charged states and phase segregation are described in the framework
of the phenomenological Ginzburg-Landau theory of phase transitions. The
Coulomb interactions determines the charge distribution and the characteristic
length of the phase separated states. The phase separation with charge
segregation becomes possible because of the large dielectric constant and the
small density of extra charge in the range of charge localization. The phase
diagram is calculated and the energy gain of the phase separated state is
estimated. The role of the Coulomb interaction is elucidated
Properties of the barium strontium titanate film on the silicon substrate
The reported study was supported of the Russian Foundation for Basic Research, research project No. 18-42-160005. The work is partially performed according to the Russian Government Program of Competitive Growth of Kazan Federal University. A.S. Elshin thanks the Russian Foundation for Basic Research for financial support, project No. 17-32-50047
The LBNO long-baseline oscillation sensitivities with two conventional neutrino beams at different baselines
The proposed Long Baseline Neutrino Observatory (LBNO) initially consists of
kton liquid double phase TPC complemented by a magnetised iron
calorimeter, to be installed at the Pyh\"asalmi mine, at a distance of 2300 km
from CERN. The conventional neutrino beam is produced by 400 GeV protons
accelerated at the SPS accelerator delivering 700 kW of power. The long
baseline provides a unique opportunity to study neutrino flavour oscillations
over their 1st and 2nd oscillation maxima exploring the behaviour, and
distinguishing effects arising from and matter. In this paper we
show how this comprehensive physics case can be further enhanced and
complemented if a neutrino beam produced at the Protvino IHEP accelerator
complex, at a distance of 1160 km, and with modest power of 450 kW is aimed
towards the same far detectors. We show that the coupling of two independent
sub-MW conventional neutrino and antineutrino beams at different baselines from
CERN and Protvino will allow to measure CP violation in the leptonic sector at
a confidence level of at least for 50\% of the true values of
with a 20 kton detector. With a far detector of 70 kton, the
combination allows a sensitivity for 75\% of the true values of
after 10 years of running. Running two independent neutrino
beams, each at a power below 1 MW, is more within today's state of the art than
the long-term operation of a new single high-energy multi-MW facility, which
has several technical challenges and will likely require a learning curve.Comment: 21 pages, 12 figure
Epizootic Situation in the Crimean Federal District as Follows from Epidemiological Survey Results, 2014
The territory of the Crimean Peninsula is an endemic one as regards various natural-focal infections. The paper contains the data on epizootiological survey of 8 administrative regions of the Crimean Federal District (CFD). Carried out has been small mammals and Ixodidae ticks census. Identified is their species composition. Performed have been the field samples collection and laboratory studies for the presence of bacterial and viral infection agents. Established is the fact that H. marginatum is a dominating species among the ticks, collected during the spring season, while the house mouse prevails among the small mammals. As for the autumn collection of samples, the dominating species are H. punctata and common vole, respectively. Laboratory investigation results indicate the circulation of the agents of Ku fever, tick-borne spotty fever, Ixodidae tick-borne borreliosis, human granulocytic anaplasmosis, monocytic ehrlichiosis, hemorrhagic fever with renal syndrome and leptospirosis
A primary electron beam facility at CERN -- eSPS Conceptual design report
The design of a primary electron beam facility at CERN is described. The
study has been carried out within the framework of the wider Physics Beyond
Colliders study. It re-enables the Super Proton Synchrotron (SPS) as an
electron accelerator, and leverages the development invested in Compact Linear
Collider (CLIC) technology for its injector and as an accelerator research and
development infrastructure. The facility would be relevant for several of the
key priorities in the 2020 update of the European Strategy for Particle
Physics, such as an electron-positron Higgs factory, accelerator R\&D, dark
sector physics, and neutrino physics. In addition, it could serve experiments
in nuclear physics. The electron beam delivered by this facility would provide
access to light dark matter production significantly beyond the targets
predicted by a thermal dark matter origin, and for natures of dark matter
particles that are not accessible by direct detection experiments. It would
also enable electro-nuclear measurements crucial for precise modelling the
energy dependence of neutrino-nucleus interactions, which is needed to
precisely measure neutrino oscillations as a function of energy. The
implementation of the facility is the natural next step in the development of
X-band high-gradient acceleration technology, a key technology for compact and
cost-effective electron/positron linacs. It would also become the only facility
with multi-GeV drive bunches and truly independent electron witness bunches for
plasma wakefield acceleration. A second phase capable to deliver positron
witness bunches would make it a complete facility for plasma wakefield collider
studies. [...
Theta_13: phenomenology, present status and prospect
The leptonic mixing angle theta_13 is currently a high-priority topic in the
field of neutrino physics, with five experiments under way, searching for
neutrino oscillations induced by this angle. We review the phenomenology of
theta_13 and discuss the information from present global oscillation data. A
description of the upcoming reactor and accelerator experiments searching for a
non-zero value of theta_13 is given, and we evaluate the sensitivity reach
within the next few years.Comment: Topical review, 55 pages, 23 figures, v2: various minor improvements,
references added, new section 6, matches version to appear in J. Phys.
Experimental Observation of Plasma Wakefield Growth Driven by the Seeded Self-Modulation of a Proton Bunch
We measure the effects of transverse wakefields driven by a relativistic proton bunch in plasma with densities of 2.1 x 10(14) and 7.7 x 10(14) electrons/cm(3). We show that these wakefields periodically defocus the proton bunch itself, consistently with the development of the seeded self-modulation process. We show that the defocusing increases both along the bunch and along the plasma by using time resolved and time-integrated measurements of the proton bunch transverse distribution. We evaluate the transverse wakefield amplitudes and show that they exceed their seed value (< 15 MV/m) and reach over 300 MV/m. All these results confirm the development of the seeded self-modulation process, a necessary condition for external injection of low energy and acceleration of electrons to multi-GeV energy levels
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