1,538 research outputs found

    ENDOVENOUS LASER ABLATION OF MAIN SUPERFICIAL VEINS: FIRST APPLICATION IN EAST SIBERIA

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    The aim of the work was to evaluate the effectiveness of endovenous laser ablation of great and small saphenous veins by a series of clinical cases of patients with varicose veins. Endovenous laser ablation of great (18) and small saphenous veins (8) were performed in 24 patients. This surgery was combined with phlebectomy varicose veins in 16 and foam form sclerotherapy in 10 cases. All patients werefollowed up for 2 and 6 months. Full ablation of main saphenous vein achieved in all patients in the early period of observation. Endovenous laser ablation of main saphenous veins is a good alternative to standard flebectomy it has the same with the surgery percentage of recurrence in early period of observation but faster rehabilitation after interference. Further control clinical study is needed for assessment effect of this treatment in the course of year and more

    Anticholinergic activity and pharmacokinetic parameters of agent SS-68 with properties of class III antiarrhythmic drugs

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    It was shown that the indole derivate SS-68 (50 and 250 μg/kg intravenous) in acute experiments on cats with neurogenic atrial fibrillation (AF) has a dose-dependent antiarrhythmic action which is associated with the neurotropic influence of this substance, since the suppression of the AF coincides with its anticholinergic effect observed for more than 2 hours, but cardiotropic action at this time was not observed. High antiarrhythmic activity of SS-68 to neurogenic AF may be due to the IKAch inhibition and blockade of M2-cholinergic receptor

    Escape of the martian protoatmosphere and initial water inventory

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    Latest research in planet formation indicate that Mars formed within a few million years (Myr) and remained a planetary embryo that never grew to a more massive planet. It can also be expected from dynamical models, that most of Mars' building blocks consisted of material that formed in orbital locations just beyond the ice line which could have contained ~0.1-0.2 wt. % of H2O. By using these constraints, we estimate the nebula-captured and catastrophically outgassed volatile contents during the solidification of Mars' magma ocean and apply a hydrodynamic upper atmosphere model for the study of the soft X-ray and extreme ultraviolet (XUV) driven thermal escape of the martian protoatmosphere during the early active epoch of the young Sun. The amount of gas that has been captured from the protoplanetary disk into the planetary atmosphere is calculated by solving the hydrostatic structure equations in the protoplanetary nebula. Depending on nebular properties such as the dust grain depletion factor, planetesimal accretion rates and luminosities, hydrogen envelopes with masses >=3x10^{19} g to <=6.5x10^{22} g could have been captured from the nebula around early Mars. Depending of the before mentioned parameters, due to the planets low gravity and a solar XUV flux that was ~100 times stronger compared to the present value, our results indicate that early Mars would have lost its nebular captured hydrogen envelope after the nebula gas evaporated, during a fast period of ~0.1-7.5 Myr. After the solidification of early Mars' magma ocean, catastrophically outgassed volatiles with the amount of ~50-250 bar H2O and ~10-55 bar CO2 could have been lost during ~0.4-12 Myr, if the impact related energy flux of large planetesimals and small embryos to the planet's surface lasted long enough, that the steam atmosphere could have been prevented from condensing. If this was not the case... (continued)Comment: 47 pages, 10 figures, 3 tables, submitted to PS

    Minimizing the negativity of quantum circuits in overcomplete quasiprobability representations

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    The problem of simulatability of quantum processes using classical resources plays a cornerstone role for quantum computing. Quantum circuits can be simulated classically, e.g., using Monte Carlo sampling techniques applied to quasiprobability representations of circuits' basic elements, i.e., states, gates, and measurements. The effectiveness of the simulation is determined by the amount of the negativity in the representation of these basic elements. Here we develop an approach for minimizing the total negativity of a given quantum circuit with respect to quasiprobability representations, that are overcomplete, i.e., are such that the dimensionality of corresponding quasistochastic vectors and matrices is larger than the squared dimension of quantum states. Our approach includes both optimization over equivalent quasistochastic vectors and matrices, which appear due to the overcompleteness, and optimization over overcomplete frames. We demonstrate the performance of the developed approach on some illustrative cases, and show its significant advantage compared to the standard overcomplete quasistochastic representations. We also study the negativity minimization of noisy brick-wall random circuits via a combination of increasing frame dimension and applying gate merging technique. We demonstrate that the former approach appears to be more efficient in the case of a strong decoherence.Comment: 15 pages, 8 figure

    Investigation of the properties of the CoCrFeMnNi alloy developed on the basis of the entropy approach

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    The paper presents the results of studying some properties and structure of a quasi high-entropy alloy (QHEA) of the CoCrFeMnNi system melted with the use of ferroalloys. The paper presents the results of a study of some properties and structure of a quasi-high-entropy alloy of the CoCrFeMnNi system, smelted using low-carbon ferromanganese and ferrochrome. Chemical composition, strength and microhardness have been studied. The structure contains a small number of inclusions of silicate nature. The experimental alloy demonstrated properties close to the level of properties of a similar alloy melted with the use of pure metals by 5-fold remelting. The results obtained showed the possibility of partial replacement of pure metals with ferroalloys when smelting of QHEAs, which will positively affect their cost

    Chromium-nickel cast iron composition effect on properties and graphitization process

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    The paper considers the cast iron based on nihard-2 composition effect on the properties and process of graphitization. It is shown that changing the Cr:Si ratio equal to 2:1 leads to the development of the graphitization process, as a result of which lamellar graphite appears in the structure. Subsequent modification leads to changing the shape of the graphite into the nodular one, which leads to some decrease in hardness but increases resistance to abrasive wear by about 20-25 %
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