496 research outputs found
Posterior interosseous nerve palsy secondary to pigmented villonodular synovitis of the elbow: Case report and review of literature
SummaryLocal tumor compression is the main mechanical cause of posterior interosseous nerve (PIN) palsy. The reported cases of these tumors do not include that of pigmented villonodular synovitis (PVNS). Here, we report a case of a 53-year-old male with a 9-year history of painless swelling in his left elbow and a few months of progressive weakness in his left hand. Imaging identified the mass, and histological examination of the biopsy specimens revealed PVNS. The mass was compressing the nerve at the arcade of Frohse, and we performed a complete resection of the mass. Following removal of the mass, the patient regained complete function in his left upper extremity, and no local recurrence has been detected after 2 postoperative years. The possibility of PVNS should be considered in the differential diagnosis of PIN palsy
Identification of an RNA Silencing Suppressor Encoded by a Symptomless Fungal Hypovirus, Cryphonectria Hypovirus 4
Previously, we have reported the ability of a symptomless hypovirus Cryphonectria hypovirus 4 (CHV4) of the chestnut blight fungus to facilitate stable infection by a co-infecting mycoreovirus 2 (MyRV2)—likely through the inhibitory effect of CHV4 on RNA silencing (Aulia et al., Virology, 2019). In this study, the N-terminal portion of the CHV4 polyprotein, termed p24, is identified as an autocatalytic protease capable of suppressing host antiviral RNA silencing. Using a bacterial expression system, CHV4 p24 is shown to cleave autocatalytically at the di-glycine peptide (Gly214-Gly215) of the polyprotein through its protease activity. Transgenic expression of CHV4 p24 in Cryphonectria parasitica suppresses the induction of one of the key genes of the antiviral RNA silencing, dicer-like 2, and stabilizes the infection of RNA silencing-susceptible virus MyRV2. This study shows functional similarity between CHV4 p24 and its homolog p29, encoded by the symptomatic prototype hypovirus CHV1
Nonpolar optical scattering of positronium in magnesium fluoride
We report the results of the analysis of the temperature broadening of the
momentum distribution of delocalized Positronium (Ps) in Magnesium Fluoride in
terms of optical deformation-potential scattering model (long-wavelength
optical phonons). The Ps optical deformation-potential coupling constant
in MgF has been determined to be eV/cm.
We also show that the Ps momentum distribution is sensitive to second-order
phase transitions in those crystals where optical deformation-potential
scattering is allowed in one and forbidden in another crystalline phase
Variational calculation of the ppK^- system based on chiral SU(3) dynamics
The ppK^- system, as a prototype for possible quasibound Kbar nuclei,is
investigated using a variational approach. Several versions of energy dependent
effective KbarN interactions derived from chiral SU(3) dynamics are employed as
input, together with a realistic NN potential (Av18). Taking into account
theoretical uncertainties in the extrapolations below the KbarN threshold, we
find that the antikaonic dibaryon ppK^- is NOT deeply bound. With the driving
s-wave KbarN interaction the resulting total binding energy is B(ppK^-) = 20
3 MeV and the mesonic decay width involving KbarN -> \pi Y is expected to
be in the range 40 - 70 MeV. Properties of this quasibound ppK^- system (such
as density distributions of nucleons and antikaon) are discussed. The
\Lambda(1405), as an I=0 quasi-bound state of Kbar and a nucleon, appears to
survive in the ppK^- cluster. Estimates are given for the influence of p-wave
KbarN interactions and for the width from two-nucleon absorption (KbarNN -> YN)
processes. With inclusionof these effects and dispersive corrections from
absorption, the ppK^- binding energy is expected to be in the range 20 - 40
MeV, while the total decay width can reach 100 MeV but with large theoretical
uncertainties.Comment: 18 pages, 12 figures, Resubmitted to Phys. Rev.
Constraining the low-energy S=-2 meson-baryon interaction with two-particle correlations
The two-particle correlation technique applied to pairs in pp
collisions at LHC recently provided the most precise data on the strangeness
meson-baryon interaction. In this letter, we use for the first time
femtoscopic data to constrain the parameters of a low-energy effective QCD
Lagrangian. The tuned model delivers new insights on the molecular nature of
the and states. This procedure opens the possibility to
determine higher order corrections, directly constraining QCD effective models
particularly in the multi-strange and charm sectors
Separable potential model for interactions at low energies
The effective separable meson-baryon potentials are constructed to match the
equivalent chiral amplitudes up to the second order in external meson momenta.
We fit the model parameters (low energy constants) to the threshold and low
energy data. In the process, the -proton bound state problem is
solved exactly in the momentum space and the 1s level characteristics of the
kaonic hydrogen are computed simultaneously with the available low energy
cross sections. The model is also used to describe the
mass spectrum and the energy dependence of the amplitude.Comment: 31 pages, v2 - added corrections to make it compatible with the
published versio
Kaon induced Lambda(1405) production on a deuteron target at DAFNE
The K^- induced production of Lambda(1405) in the K^- d to pi Sigma n
reaction is investigated having in mind the conditions of the DAFNE facility at
Frascati where kaons are obtained from the decay of slow moving phi mesons. We
find that the K^- d to Lambda(1405) n process favors the production of
Lambda(1405) initiated by the K^- p channel, which gives largest weight to the
higher mass Lambda(1405) appearing at 1420 MeV in chiral theories. We find that
the fastest kaons from the decay of the phi are well suited to see this
resonance, particularly if one selects forward going neutrons in the center of
mass, which reduce the contribution of single scattering and make the double
scattering dominate where the signal of the resonance appears clearer.Comment: 6pages, 7 figure
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