106 research outputs found
PECULIARITIES OF HIP JOINT PROSTHESIS IN PATIENTS WITH RHEUMATOID ARTHRITIS
The aim. To improve the results of treatment of patients with rheumatic lesions of the hip joint by choosing the best options for endoprosthetics and postoperative rehabilitation of pa-tients. Materials and research methods. The object of the study was 125 patients with RA with TBS lesion, who underwent TB TBS in the Department of Adult Orthopedics of the UzNII of Traumatology and Orthopedics and the Department of Traumatology of the Clinical Hospital No. 1 for the period 2011 to 2017. In the foreground of preoperative planning, patients received conservative treatment on an outpatient basis for 2 weeks from a rheumatologist. After normali-zation of the rheumatic test indices, the patients came to us for surgical treatment. All patients were divided into 2 groups - the main and control. The main group consisted of 75 patients; in addition to the traditional method of surgical treatment, they used a device developed by us to determine the depth of the acetabulum during surgery, which made it possible to atraumatically, accurately and quickly determine the landing depth of the acetabular component of the endoprosthesis. Also, after surgery, the developed splint was used to develop the TB joint. The control group included 50 patients who underwent traditional methods of surgical treatment and after surgery without using a tire to rehabilitate patients. The age of patients ranged from 18 to 75 years, on average - 38 years. Of the total number of 125 sick men, there were 50 (40%), women 75 (60%). Results. Evaluation of long-term treatment results showed that good results in the main group (81.5%) were significantly greater than the control group (75%). Unsatisfactory results were obtained in patients of the main (1.5%) and control groups (5%). Conclusion. In the treatment of patients with RA, the use of cementless endoprostheses provides the possibility of widespread introduction of TBS endoprosthetics. In patients with RA with severe osteoporosis, protrusive coxitis and defects in the walls of the acetabulum, the justi-fied method is TE TBS using bone cement
Superconductive proximity effect in interacting disordered conductors
We present a general theory of the superconductive proximity effect in
disordered normal--superconducting (N-S) structures, based on the recently
developed Keldysh action approach. In the case of the absence of interaction in
the normal conductor we reproduce known results for the Andreev conductance G_A
at arbitrary relation between the interface resistance R_T and the diffusive
resistance R_D. In two-dimensional N-S systems, electron-electron interaction
in the Cooper channel of normal conductor is shown to strongly affect the value
of G_A as well as its dependence on temperature, voltage and magnetic field. In
particular, an unusual maximum of G_A as a function of temperature and/or
magnetic field is predicted for some range of parameters R_D and R_T. The
Keldysh action approach makes it possible to calculate the full statistics of
charge transfer in such structures. As an application of this method, we
calculate the noise power of an N-S contact as a function of voltage,
temperature, magnetic field and frequency for arbitrary Cooper repulsion in the
normal metal and arbitrary values of the ratio R_D/R_T.Comment: RevTeX, 28 pages, 18 PostScript figures; added and updated reference
Theory of Interaction Effects in N-S Junctions out of Equilibrium
We consider a normal metal - superconductor (N-S) junction in the regime,
when electrons in the normal metal are driven out of equilibrium. We show that
the non-equilibrium fluctuations of the electron density in the N-layer cause
the fluctuations of the phase of the order parameter in the S-layer. As a
result, the density of states in the superconductor deviates from the BCS form,
most notably the density of states in the gap becomes finite. This effect can
be viewed as a result of the time reversal symmetry breaking due to the
non-equilibrium, and can be described in terms of a low energy collective mode
of the junction, which couples normal currents in N-layer and supercurrents.
This mode is analogous to the Schmid-Sch\"{o}n mode. To interpret their
measurements of the tunneling current, Pothier {\em et. al} [Phys. Rev. Lett.
{\bf 79}, 3490 (1997)] had to assume that the energy relaxation rate in the
normal metal is surprisingly high. The broadening of the BCS singularity of the
density of states in the S-layer manifest itself similarly to the broadening of
the distribution function. Mechanism suggested here can be a possible
explanation of this experimental puzzle. We also propose an independent
experiment to test our explanation.Comment: 16 pages, 2 .eps figure
Fractional plateaus in the Coulomb blockade of coupled quantum dots
Ground-state properties of a double-large-dot sample connected to a reservoir
via a single-mode point contact are investigated. When the interdot
transmission is perfect and the dots controlled by the same dimensionless gate
voltage, we find that for any finite backscattering from the barrier between
the lead and the left dot, the average dot charge exhibits a Coulomb-staircase
behavior with steps of size e/2 and the capacitance peak period is halved. The
interdot electrostatic coupling here is weak. For strong tunneling between the
left dot and the lead, we report a conspicuous intermediate phase in which the
fractional plateaus get substantially altered by an increasing slope.Comment: 6 pages, 4 figures, final versio
Direct synthesized graphene-like film on SiO₂: Mechanical and optical properties
Exploiting CVD technique for carbon deposition from C₂H₂+H₂+N₂ mixture, a graphene-like film synthesized directly on SiO₂ surface of SiO₂-Si structure was obtained. The graphene-like film was grown under thin Ni layer that is easy exfoliated from graphene-SiO₂-Si structure. Surface of the film was sufficiently smooth and reveals no winkles and holes; it has a good homogeneity and perfect adhesion to SiO₂ layer. Studying the micro-Raman spectra showed a graphene-like structure of the film; using atomic force microscopic technique, the thickness of film was determined (0.6 nm). Using spectroscopic ellipsometry and simple Cauchy model enabled us to estimate optical parameters of this graphene-like film
Shot Noise at High Temperatures
We consider the possibility of measuring non-equilibrium properties of the
current correlation functions at high temperatures (and small bias). Through
the example of the third cumulant of the current () we demonstrate
that odd order correlation functions represent non-equilibrium physics even at
small external bias and high temperatures. We calculate for a quasi-one-dimensional diffusive constriction. We calculate the
scaling function in two regimes: when the scattering processes are purely
elastic and when the inelastic electron-electron scattering is strong. In both
cases we find that interpolates between two constants. In the low (high)
temperature limit is strongly (weakly) enhanced (suppressed) by the
electron-electron scattering.Comment: 11 pages 4 fig. submitted to Phys. Rev.
Coulomb effects in granular materials at not very low temperatures
We consider effects of Coulomb interaction in a granular normal metal at not
very low temperatures suppressing weak localization effects. In this limit
calculations with the initial electron Hamiltonian are reduced to integrations
over a phase variable with an effective action, which can be considered as a
bosonization for the granular metal. Conditions of the applicability of the
effective action are considered in detail and importance of winding numbers for
the phase variables is emphasized. Explicit calculations are carried out for
the conductivity and the tunneling density of states in the limits of large
and small tunnelling conductances. It is demonstrated for any
dimension of the array of the grains that at small the conductivity and the
tunnelling density of states decay with temperature exponentially. At large
the conductivity also decays with decreasing the temparature and its
temperature dependence is logarithmic independent of dimensionality and
presence of a magnetic field. The tunnelling density of states for is
anomalous in any dimension but the anomaly is stronger than logarithmic in low
dimensions and is similar to that for disordered systems. The formulae derived
are compared with existing experiments. The logarithmic behavior of the
conductivity at large obtained in our model can explain numerous
experiments on systems with a granular structure including some high
materials.Comment: 30 page
Anisotropic flow of charged hadrons, pions and (anti-)protons measured at high transverse momentum in Pb-Pb collisions at TeV
The elliptic, , triangular, , and quadrangular, , azimuthal
anisotropic flow coefficients are measured for unidentified charged particles,
pions and (anti-)protons in Pb-Pb collisions at TeV
with the ALICE detector at the Large Hadron Collider. Results obtained with the
event plane and four-particle cumulant methods are reported for the
pseudo-rapidity range at different collision centralities and as a
function of transverse momentum, , out to GeV/.
The observed non-zero elliptic and triangular flow depends only weakly on
transverse momentum for GeV/. The small dependence
of the difference between elliptic flow results obtained from the event plane
and four-particle cumulant methods suggests a common origin of flow
fluctuations up to GeV/. The magnitude of the (anti-)proton
elliptic and triangular flow is larger than that of pions out to at least
GeV/ indicating that the particle type dependence persists out
to high .Comment: 16 pages, 5 captioned figures, authors from page 11, published
version, figures at http://aliceinfo.cern.ch/ArtSubmission/node/186
Centrality dependence of charged particle production at large transverse momentum in Pb-Pb collisions at TeV
The inclusive transverse momentum () distributions of primary
charged particles are measured in the pseudo-rapidity range as a
function of event centrality in Pb-Pb collisions at
TeV with ALICE at the LHC. The data are presented in the range
GeV/ for nine centrality intervals from 70-80% to 0-5%.
The Pb-Pb spectra are presented in terms of the nuclear modification factor
using a pp reference spectrum measured at the same collision
energy. We observe that the suppression of high- particles strongly
depends on event centrality. In central collisions (0-5%) the yield is most
suppressed with at -7 GeV/. Above
GeV/, there is a significant rise in the nuclear modification
factor, which reaches for GeV/. In
peripheral collisions (70-80%), the suppression is weaker with almost independently of . The measured nuclear
modification factors are compared to other measurements and model calculations.Comment: 17 pages, 4 captioned figures, 2 tables, authors from page 12,
published version, figures at
http://aliceinfo.cern.ch/ArtSubmission/node/284
Two-pion Bose-Einstein correlations in central Pb-Pb collisions at = 2.76 TeV
The first measurement of two-pion Bose-Einstein correlations in central Pb-Pb
collisions at TeV at the Large Hadron Collider is
presented. We observe a growing trend with energy now not only for the
longitudinal and the outward but also for the sideward pion source radius. The
pion homogeneity volume and the decoupling time are significantly larger than
those measured at RHIC.Comment: 17 pages, 5 captioned figures, 1 table, authors from page 12,
published version, figures at
http://aliceinfo.cern.ch/ArtSubmission/node/388
- …