642 research outputs found
Functional changes in motor endplates of the target muscle after amputation of the C7 nerve root
There are limited data on structural and functional changes in motor endplates and
muscle fibers in the target muscle following amputation of the 7th cervical nerve root, a
transplantation-related procedure in surgical treatment in the case of avulsions of the brachial
plexus roots. We examined functional changes in these structures using stimulated singlefiber electromyography (sSF-EMG) in an animal model. Unilateral amputation of the 7th
cervical nerve root was performed in 36 male rats, and the m. triceps brachii muscle was
tested by sSF-EMG at different time points. We observed significant differences in the jitter
(mean consecutive difference, MCD, of the latencies between adjacent muscle fibers) at postamputation weeks 1, 2, 4, and 6. The post-operation fiber density (FD) values within the
zone of effective stimulation also gradually increased. At post-amputation weeks 8 and 12,
the jitter values returned to normal levels, whereas FD values continued to rise. Our results
indicate that the post-amputation compensatory processes in the target muscles of the 7th
cervical nerve root are completed at 9-12 weeks after amputation.Дані щодо структурних та функціональних змін у моторних
кінцевих пластинках та м’язових волокнах м’яза-цілі після ампутації сьомого шийного нервового корінця (процедури в рамках трансплантаційного хірургічного лікування
наслідків відриву корінців брахіального сплетіння) поки
що обмежені. Ми досліджували функціональні зміни в згаданих структурах, використовуючи методику стимуляційної „одноволоконної” електроміографії в умовах експериментальної моделі на тваринах. Унілатеральну ампутацію
сьомого цервікального нервового корінця було виконано на
36 щурах-самцях, і триголові м’язи плеча тестувалися за допомогою згаданої ЕМГ-методики в різні часові інтервали.
Ми виявили істотні відмінності середніх варіацій („дрижання”, jitter, різниць між послідовними величинами) латентних періодів, характерних для прилеглих одне до одного
м’язових волокон, у перший, другий, четвертий та шостий
тижні після операційного періоду. В цей час щільність волокон у зоні ефективної стимуляції також поступово зростала.
На восьмий–12-й тижні післяопераційного періоду значення варіацій („дрижання”) поверталися до нормальних, тоді
як значення щільності активованих волокон продовжували
зростати. Наші результати свідчать про те, що післяампутаційні компенсаторні процеси в м’язах-цілях волокон нервового корінця С7 завершуються через дев’ять–12 тижнів після ампутації останнього
Phantom Field with O(N) Symmetry in Exponential Potential
In this paper, we study the phase space of phantom model with O(\emph{N})
symmetry in exponential potential. Different from the model without O(\emph{N})
symmetry, the introduction of the symmetry leads to a lower bound on the
equation of state for the existence of stable phantom dominated attractor
phase. The reconstruction relation between the potential of O(\textit{N})
phantom system and red shift has been derived.Comment: 5 pages, 3 figures, replaced with the version to appear on Phys. Rev.
Opacity calculation for target physics using the ABAKO/RAPCAL code
Radiative properties of hot dense plasmas remain a subject of current interest since they play an important role in inertial confinement fusion (ICF) research, as well as in studies on stellar physics. In particular, the understanding of ICF plasmas requires emissivities and opacities for both hydro-simulations and diagnostics. Nevertheless, the accurate calculation of these properties is still an open question and continuous efforts are being made to develop new models and numerical codes that can facilitate the evaluation of such properties. In this work the set of atomic models ABAKO/RAPCAL is presented, as well as a series of results for carbon and aluminum to show its capability for modeling the population kinetics of plasmas in both LTE and NLTE regimes. Also, the spectroscopic diagnostics of a laser-produced aluminum plasma using ABAKO/RAPCAL is discussed. Additionally, as an interesting application of these codes, fitting analytical formulas for Rosseland and Planck mean opacities for carbon plasmas are reported. These formulas are useful as input data in hydrodynamic simulation of targets where the computation task is so hard that in line computation with sophisticated opacity codes is prohibitive
Search for Invisible Decays of and in and
Using a data sample of decays collected with the BES
II detector at the BEPC, searches for invisible decays of and
in to and are performed.
The signals, which are reconstructed in final states, are used
to tag the and decays. No signals are found for the
invisible decays of either or , and upper limits at the 90%
confidence level are determined to be for the ratio
and for . These are the first
searches for and decays into invisible final states.Comment: 5 pages, 4 figures; Added references, Corrected typo
Defect structures and torque on an elongated colloidal particle immersed in a liquid crystal host
Combining molecular dynamics and Monte Carlo simulation we study defect
structures around an elongated colloidal particle embedded in a nematic liquid
crystal host. By studying nematic ordering near the particle and the
disclination core region we are able to examine the defect core structure and
the difference between two simulation techniques. In addition, we also study
the torque on a particle tilted with respect to the director, and modification
of this torque when the particle is close to the cell wall
Observation of Two New N* Peaks in J/psi -> and Decays
The system in decays of is limited to be
isospin 1/2 by isospin conservation. This provides a big advantage in studying
compared with and experiments which mix
isospin 1/2 and 3/2 for the system. Using 58 million decays
collected with the Beijing Electron Positron Collider, more than 100 thousand
events are obtained. Besides two well known
peaks at 1500 MeV and 1670 MeV, there are two new, clear peaks in
the invariant mass spectrum around 1360 MeV and 2030 MeV. They are the
first direct observation of the peak and a long-sought "missing"
peak above 2 GeV in the invariant mass spectrum. A simple
Breit-Wigner fit gives the mass and width for the peak as MeV and MeV, and for the new peak above 2 GeV
as MeV and MeV, respectively
Effective local connectivity properties
We investigate, and prove equivalent, effective versions of local
connectivity and uniformly local arcwise connectivity for connected and
computably compact subspaces of Euclidean space. We also prove that Euclidean
continua that are computably compact and effectively locally connected are
computably arcwise connected.Comment: Final versio
Partial Wave Analysis of
BES data on are presented. The
contribution peaks strongly near threshold. It is fitted with a
broad resonance with mass MeV, width MeV. A broad resonance peaking at 2020 MeV is also required
with width MeV. There is further evidence for a component
peaking at 2.55 GeV. The non- contribution is close to phase
space; it peaks at 2.6 GeV and is very different from .Comment: 15 pages, 6 figures, 1 table, Submitted to PL
Search for the Rare Decays J/Psi --> Ds- e+ nu_e, J/Psi --> D- e+ nu_e, and J/Psi --> D0bar e+ e-
We report on a search for the decays J/Psi --> Ds- e+ nu_e + c.c., J/Psi -->
D- e+ nu_e + c.c., and J/Psi --> D0bar e+ e- + c.c. in a sample of 5.8 * 10^7
J/Psi events collected with the BESII detector at the BEPC. No excess of signal
above background is observed, and 90% confidence level upper limits on the
branching fractions are set: B(J/Psi --> Ds- e+ nu_e + c.c.)<4.8*10^-5, B(J/Psi
--> D- e+ nu_e + c.c.) D0bar e+ e- + c.c.)<1.1*10^-5Comment: 10 pages, 4 figure
Study of J/psi decays to Lambda Lambdabar and Sigma0 Sigma0bar
The branching ratios and Angular distributions for J/psi decays to Lambda
Lambdabar and Sigma0 Sigma0bar are measured using BESII 58 million J/psi.Comment: 11 pages, 5 figure
- …