92 research outputs found

    Comparative analysis of postoperative results of cataract surgery using monofocal IOLs

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    One of the most common surgical interventions in ophthalmology today is lens replacement surgery. But there is still no consensus on whether the choice of a monofocal IOL affects the postoperative functional outcome.The aim: to conduct a comparative analysis of values of visual acuity without correction in the early postoperative period after cataract surgery using monofocal IOLs.Material and methods. The study included data of 2643 eyes operated for cataract, into which one of the monofocal IOLs, included in the top ten most frequently implanted IOLs in the Orenburg Branch of the S. Fyodorov Eye Microsurgery Federal State Institution, was implanted for the period 2019–2021. Statistical analysis was performed using the program Statistica 13.0.Results. The performed analysis of variance showed that the established differences between the compared groups are statistically signifi cant (p < 0.05). However, the subgroup analysis showed that there were statistically signifi cant differences between pairs such as Tecnis and Hydro-4; Tecnis and Rayner. In all other cases, statistically signifi cant uncorrected visual activity (UCVA) values after surgery were not established. It has also been reliably established that the presence of subluxation of the lens affects the value of UCVA after surgery.Conclusion. The results of the performed analysis in general indicate that the value of UCVA in patients in the early postoperative period after the performed surgical intervention does not depend on the manufacturer of the used IOL

    Infrared signatures of charge stripes in La(2-x)Sr(x)CuO(4)

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    The in-plane optical conductivity of seven La(2-x)Sr(x)CuO(4) single crystals with x between 0 and 0.15 has been studied from 30 to 295 K. All doped samples exhibit strong peaks in the far-infrared, which closely resemble those observed in Cu-O "ladders" with one-dimensional charge-ordering. The behavior with doping and temperature of the peak energy, width, and intensity allows us to conclude that we are observing charge stripes dynamics in La(2-x)Sr(x)CuO(4) on the fast time scale of infrared spectroscopy.Comment: 9 pages including figs. in pdf forma

    Raman Scattering versus Infrared Conductivity: Evidence for one-dimensional Conduction in La_{2-x}Sr_{x}CuO_{4}

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    Raman and Infrared (IR) spectra of an underdoped La_{1.90}Sr_{0.10}CuO_{4} single crystal have been measured as a function of temperature. Both techniques provide unconventional low-energy spectra. The IR conductivity exhibits features peaked at finite frequencies which do not have a counterpart in the Raman response. Below approximately 100 K a transfer of both Raman and IR spectral weight towards lower energies is found and a new component in the Raman response builds up being characterized by a very long lifetime of electrons propagating along the Cu-O bonds.Comment: 4 pages, 3 eps figure

    Anomalous optical absorption in overdoped cuprates near the charge-ordering instability

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    We propose an interpretation for the hump observed in the optical conductivity at or below a few hundreds of cm1^{-1}, in overdoped cuprates like the electron-doped Nd_{2-x}Ce_xCuO_{4-y} at x\gtrsim 0.15 and the hole-doped Bi_2Sr_2CuO_6 and La_{2-x}Sr_xCuO_4. This interpretation is based on the direct excitation of charge collective modes, which become nearly critical in the proximity to a charge-ordering instability. The nearly critical character of these excitations entails a peculiar temperature dependence and a pseudo-scaling form of the lineshapes, which are in agreement with the experimental data.Comment: 5 pages, 3 figure

    Physical therapy methods in the treatment and rehabilitation of cancer patients

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    The results of the effective use of magnetic laser therapy in the treatment and rehabilitation of cancer patients were presented. The effect of magnetic-laser therapy in the treatment of radiation-induced reactions in the patients with head and neck cancer and in the patients with breast cancer was analyzed. High efficiency of lymphedema and lymphorrhea treatment in the postoperative period in the patients with breast cancer was proved. The results of rehabilitation of the patients with gastric cancer after surgical treatment were presented. These data indicate a high effectiveness of different physical methods of treatment and rehabilitation of cancer patients

    Kerr-Gauss-Bonnet Black Holes: An Analytical Approximation

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    Gauss-Bonnet gravity provides one of the most promising frameworks to study curvature corrections to the Einstein action in supersymmetric string theories, while avoiding ghosts and keeping second order field equations. Although Schwarzschild-type solutions for Gauss-Bonnet black holes have been known for long, the Kerr-Gauss-Bonnet metric is missing. In this paper, a five dimensional Gauss-Bonnet approximation is analytically derived for spinning black holes and the related thermodynamical properties are briefly outlined.Comment: 5 pages, 1 figur

    The pseudogap in high-temperature superconductors: an experimental survey

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    We present an experimental review of the nature of the pseudogap in the cuprate superconductors. Evidence from various experimental techniques points to a common phenomenology. The pseudogap is seen in all high temperature superconductors and there is general agreement on the temperature and doping range where it exists. It is also becoming clear that the superconducting gap emerges from the normal state pseudogap. The d-wave nature of the order parameter holds for both the superconducting gap and the pseudogap. Although an extensive body of evidence is reviewed, a consensus on the origin of the pseudogap is as lacking as it is for the mechanism underlying high temperature superconductivity.Comment: review article, 54 pages, 50 figure

    What the resonance peak cannot do

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    In certain cuprates, a spin 1 resonance mode is prominent in the magnetic structure measured by neutron scattering. It has been proposed that this mode is responsible for significant features seen in other spectroscopies, such as photoemission and optical absorption, which are sensitive to the charge dynamics, and even that this mode is the boson responsibile for ``mediating'' the superconducting pairing. We show that its small (measured) intensity and weak coupling to electron-hole pairs (as deduced from the measured lifetime) disqualifies the resonant mode from either proposed role.Comment: 4 pages, no figur

    Structure of the Galaxies in the NGC 80 Group

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    BV-bands photometric data obtained at the 6-m telescope of the Special Astrophysical Observatory are used to analyze the structure of 13 large disk galaxies in the NGC 80 group. Nine of the 13 galaxies under consideration are classified by us as lenticular galaxies. The stellar populations in the galaxies are very different, from old ones with ages of T>10 Gyrs (IC 1541) to relatively young, with the ages of T<2-3 Gyr (IC 1548, NGC 85). In one case, current star formation is known (UCM 0018+2216). In most of the galaxies, more precisely in all of them more luminous than M(B) -18, two-tiered (`antitruncated') stellar disks are detected, whose radial surface brightness profiles can be fitted by two exponential segments with different scalelengths -- shorter near the center and longer at the periphery. All dwarf S0 galaxies with single-scalelength exponential disks are close companions to giant galaxies. Except for this fact, no dependence of the properties of S0 galaxies on distance from the center of the group is found. Morphological traces of minor merger are found in the lenticular galaxy NGC 85. Basing on the last two points, we conclude that the most probable mechanisms for the transformation of spirals into lenticular galaxies in groups are gravitational ones, namely, minor mergers and tidal interactions.Comment: 24 pages, 9 figures, slightly improved version of the paper published in the December, 2009, issue of the Astronomy Report

    Analysis of the causes of suicidal attempts among youth and mature (1st period) age to assess the need for preventive measures

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    The purpose of the study is to identify the main causes of suicidal attempts in adolescence and adulthood (1 period) in order to assess the need for preventive measures.Цель исследования – выявить основные причины суицидальных попыток в юношеском и зрелом (1 периода) возрасте для оценки необходимости профилактических мероприятий
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