43 research outputs found

    Lower pole obstructive megaureter of duplex kidney: an exception to the Weigert-Meyer rule

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    Introduction. Anatomical features of the urinary tract in patients with duplicate kidneys are described using the Weigert-Meyer rule, since the orifice of the upper ureter has an ectopic location (inferomedial) and the orifice of the lower ureter has an orthotopic location (superolateral). However, there are rare cases of violation of this rule, complicated by obstructive megaureter, ectopic ureteral orifice, the presence of ureterocele.Objective. To report the rare clinical case of a lower pole obstructive megaureter as a violation of the Meyer-Weigert rule in the patient with complete ureteral duplication and to describe the use of ureteroureterostomy as an effective and safe method of surgical correction of the presented anomaly.Clinical case. We present a case of the infant (5 months old) with a lower pole obstructive megaureter. This pathology was identified through intravenous urography and voiding cystourethrography. Laparoscopic proximal end-to-side ureteroureteroanastomosis was chosen as a surgical treatment. Postoperative control intravenous urography showed the effectiveness (a reduction in the lower pole collecting system of the duplex kidney was revealed) and the safety of this method of correction.Conclusion.  There are only several clinical cases about exceptions to the Weigert-Meyer rule reported in literature, and most of them are about adult patients. The main surgical method of treatment in such cases is heminephrectomy. To our knowledge, this is the only reported case of using ureteroureterostomy in the patient with a lower pole obstructive megaureter. This technique has shown its effectiveness and safety for restoring the patency of the urinary tract, confirmed during the control postoperative examination

    Accelerated cross-linking technique using a protective corneal donor flap in the treatment of progressive keratoconus on «thin» corneas

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    Purpose. To develop a method of accelerated ultraviolet crosslinking with an initial corneal thickness equal to or less than 400 microns using a protective donor corneal flap. Definition of safety and effectiveness of this method in the treatment of progressive keratoconus.Material and methods. 20 patients (20 eyes) with a diagnosis of progressive keratoconus 2–3 stages were included in the study. The accelerated crosslinking was carried out with an IROC-VX-2000 device (Switzerland). A protective donor corneal flap was cut out by using a Femto LDV Z8 femtosecond laser («Ziemer», Switzerland). The thickness of the protective flap of the donor cornea was determined as the difference between 450 μm and the obtained value of the patient’s pachymetry in 30 minutes of saturation with Dextralink in μm.Results. Indicators of uncorrected visual acuity and corrected visual acuity returned to the level of preoperative values and did not tend to decrease until the end of the observation period for 6 months. The average keratometry indices gradually decreased: after 3 months – 50.3±1.5 μm, after 6 months – 48.9±1.8 μm, by 12 months – 46.7±2.1 μm. A decrease in elevation indicators of the anterior and posterior surfaces was marked on elevation maps throughout the observation period.Conclusion. The proposed ultraviolet crosslinking technique using a protective donor corneal flap in patients with corneal thickness 400 μm or less is reproducible. This technique proves its effectiveness and safety and allows to stabilize the condition in patients with progressive keratoconus with adequate visual function. This makes this technique necessary, taking into account the lack of adequate cross-linking technology with a thin cornea

    Theory of differential inclusions and its application in mechanics

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    The following chapter deals with systems of differential equations with discontinuous right-hand sides. The key question is how to define the solutions of such systems. The most adequate approach is to treat discontinuous systems as systems with multivalued right-hand sides (differential inclusions). In this work three well-known definitions of solution of discontinuous system are considered. We will demonstrate the difference between these definitions and their application to different mechanical problems. Mathematical models of drilling systems with discontinuous friction torque characteristics are considered. Here, opposite to classical Coulomb symmetric friction law, the friction torque characteristic is asymmetrical. Problem of sudden load change is studied. Analytical methods of investigation of systems with such asymmetrical friction based on the use of Lyapunov functions are demonstrated. The Watt governor and Chua system are considered to show different aspects of computer modeling of discontinuous systems

    Salinity modulates thermotolerance, energy metabolism and stress response in amphipods Gammarus lacustris

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    Temperature and salinity are important abiotic factors for aquatic invertebrates. We investigated the influence of different salinity regimes on thermotolerance, energy metabolism and cellular stress defense mechanisms in amphipods Gammarus lacustris Sars from two populations. We exposed amphipods to different thermal scenarios and determined their survival as well as activity of major antioxidant enzymes (peroxidase, catalase, glutathione S-transferase) and parameters of energy metabolism (content of glucose, glycogen, ATP, ADP, AMP and lactate). Amphipods from a freshwater population were more sensitive to the thermal challenge, showing higher mortality during acute and gradual temperature change compared to their counterparts from a saline lake. A more thermotolerant population from a saline lake had high activity of antioxidant enzymes. The energy limitations of the freshwater population (indicated by low baseline glucose levels, downward shift of the critical temperature of aerobic metabolism and inability to maintain steady-state ATP levels during warming) was observed, possibly reflecting a trade-off between the energy demands for osmoregulation under the hypo-osmotic condition of a freshwater environment and protection against temperature stress

    Fast simulation of muons produced at the SHiP experiment using generative adversarial networks

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    This paper presents a fast approach to simulating muons produced in interactions of the SPS proton beams with the target of the SHiP experiment. The SHiP experiment will be able to search for new long-lived particles produced in a 400 GeV/c SPS proton beam dump and which travel distances between fifty metres and tens of kilometers. The SHiP detector needs to operate under ultra-low background conditions and requires large simulated samples of muon induced background processes. Through the use of Generative Adversarial Networks it is possible to emulate the simulation of the interaction of 400 GeV/c proton beams with the SHiP target, an otherwise computationally intensive process. For the simulation requirements of the SHiP experiment, generative networks are capable of approximating the full simulation of the dense fixed target, offering a speed increase by a factor of Script O(106). To evaluate the performance of such an approach, comparisons of the distributions of reconstructed muon momenta in SHiP's spectrometer between samples using the full simulation and samples produced through generative models are presented. The methods discussed in this paper can be generalised and applied to modelling any non-discrete multi-dimensional distribution

    The experimental facility for the Search for Hidden Particles at the CERN SPS

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    The International School for Advanced Studies (SISSA) logo The International School for Advanced Studies (SISSA) logo The following article is OPEN ACCESS The experimental facility for the Search for Hidden Particles at the CERN SPS C. Ahdida44, R. Albanese14,a, A. Alexandrov14, A. Anokhina39, S. Aoki18, G. Arduini44, E. Atkin38, N. Azorskiy29, J.J. Back54, A. Bagulya32Show full author list Published 25 March 2019 • © 2019 CERN Journal of Instrumentation, Volume 14, March 2019 Download Article PDF References Download PDF 543 Total downloads 7 7 total citations on Dimensions. Article has an altmetric score of 1 Turn on MathJax Share this article Share this content via email Share on Facebook Share on Twitter Share on Google+ Share on Mendeley Article information Abstract The Search for Hidden Particles (SHiP) Collaboration has shown that the CERN SPS accelerator with its 400 GeV/c proton beam offers a unique opportunity to explore the Hidden Sector [1–3]. The proposed experiment is an intensity frontier experiment which is capable of searching for hidden particles through both visible decays and through scattering signatures from recoil of electrons or nuclei. The high-intensity experimental facility developed by the SHiP Collaboration is based on a number of key features and developments which provide the possibility of probing a large part of the parameter space for a wide range of models with light long-lived super-weakly interacting particles with masses up to Script O(10) GeV/c2 in an environment of extremely clean background conditions. This paper describes the proposal for the experimental facility together with the most important feasibility studies. The paper focuses on the challenging new ideas behind the beam extraction and beam delivery, the proton beam dump, and the suppression of beam-induced background

    Woman movements: Preservation of ethnocultural traditions

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    © 2019, Universidad del Zulia. All rights reserved. The purpose of the article is the identification of a role of women Tatar groups of Republic of Tatarstan in public and cultural development through XX-XXI centuries via structural, historical, anthropological and functional approaches. As a result, authors seek for lighting those issues connected with the Muslim world. If there is no woman in a family, then there is no family. In conclusion, in a way of life of modern Tatar women, among youth, the activity in public and cultural and confessional life, in the revival of spiritual ethnocultural traditions of the Tatar people is shown

    Radioactive [gamma/beta] tracer to explore dangerous technogenic phenomena

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    A radioactive [gamma/beta] tracer to explore dangerous technogenic phenomena has been proposed: the ratio of the measured flux density of [beta] - and [gamma]-radiations in the surface layer of the atmosphere. The time dependence analysis of the ratio of [beta] and [gamma]-pulse count rate has been carried out. A significant increase of the [gamma/beta] ratio was recorded under the cyclone passing through Japan (Fukushima) to Kamchatka. The proposed [gamma/beta] tracer can be a very sensitive indicator of nonstationary processes related to hazardous natural and technogenic phenomena
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