92 research outputs found
Comparative analysis of postoperative results of cataract surgery using monofocal IOLs
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)
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}
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
We propose an interpretation for the hump observed in the optical
conductivity at or below a few hundreds of cm, 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
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
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
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
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
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
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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