152 research outputs found
Imaging features of aggressive fibromatosis in psoas muscle
Aggressive fibromatosis (AF) of psoas muscle origin is extremely rare and little is known about its radiological features. We here present such a case in a 24-year-old man with psoas AF and ilium bone involvement. The authors stress the contibutive diagnostic role of MRI
Generalized Misner-Sharp Energy in f(R) Gravity
We study generalized Misner-Sharp energy in gravity in a spherically
symmetric spacetime. We find that unlike the cases of Einstein gravity and
Gauss-Bonnet gravity, the existence of the generalized Misner-Sharp energy
depends on a constraint condition in the gravity. When the constraint
condition is satisfied, one can define a generalized Misner-Sharp energy, but
it cannot always be written in an explicit quasi-local form. However, such a
form can be obtained in a FRW universe and for static spherically symmetric
solutions with constant scalar curvature. In the FRW universe, the generalized
Misner-Sharp energy is nothing but the total matter energy inside a sphere with
radius , which acts as the boundary of a finite region under consideration.
The case of scalar-tensor gravity is also briefly discussed.Comment: Revtex, 17 pages, v2: some references added, to appear in PR
Hawking-Page Phase Transition of black Dp-branes and R-charged black holes with an IR Cutoff
We show that the confinement-deconfinement phase transition of supersymmetric
Yang-Mills theories with 16 supercharges in various dimensions can be realized
through the Hawking-Page phase transition between the near horizon geometries
of black Dp-branes and BPS Dp-branes by removing a small radius region in the
geometry in order to realize a confinement phase, which generalizes the
Herzog's discussion for the holographic hard-wall AdS/QCD model. Removing a
small radius region in the gravitational dual corresponds to introducing an IR
cutoff in the dual field theory. We also discuss the Hawking-Page phase
transition between thermal , , spaces and R-charged AdS
black holes coming from the spherical reduction of the decoupling limit of
rotating D3-, M2-, and M5- branes in type IIB supergravity and 11 dimensional
supergravity in grand canonical ensembles, where the IR cutoff also plays a
crucial role in the existence of the phase transition.Comment: 34 pages, 18 figures, JHEP3, v2, references added, v3, some
explanations adde
A Lifshitz Black Hole in Four Dimensional R^2 Gravity
We consider a higher derivative gravity theory in four dimensions with a
negative cosmological constant and show that vacuum solutions of both Lifshitz
type and Schr\"{o}dinger type with arbitrary dynamical exponent z exist in this
system. Then we find an analytic black hole solution which asymptotes to the
vacuum Lifshitz solution with z=3/2 at a specific value of the coupling
constant. We analyze the thermodynamic behavior of this black hole and find
that the black hole has zero entropy while non-zero temperature, which is very
similar to the case of BTZ black holes in new massive gravity at a specific
coupling. In addition, we find that the three dimensional Lifshitz black hole
recently found by E. Ayon-Beato et al. has a negative entropy and mass when the
Newton constant is taken to be positive.Comment: 11 pages, no figure; v2, a minor error correcte
Spontaneous Mirror Parity Violation, Common Origin of Matter and Dark Matter, and the LHC Signatures
Existence of a mirror world in the universe is a fundamental way to restore
the observed parity violation in weak interactions and provides the lightest
mirror nucleon as a unique GeV-scale dark matter particle candidate. The
visible and mirror worlds share the same spacetime of the universe and are
connected by a unique space-inversion symmetry -- the mirror parity (P). We
conjecture that the mirror parity is respected by the fundamental interaction
Lagrangian, and study its spontaneous breaking from minimizing the Higgs vacuum
potential. The domain wall problem is resolved by a unique soft breaking
linear-term from the P-odd weak-singlet Higgs field. We also derive constraint
from the Big-Bang nucleosynthesis. We then analyze the neutrino seesaw for both
visible and mirror worlds, and demonstrate that the desired amounts of visible
matter and mirror dark matter in the universe arise from a common origin of CP
violation in the neutrino sector via leptogenesis. We derive the Higgs
mass-spectrum and Higgs couplings with gauge bosons and fermions. We show their
consistency with the direct Higgs searches and the indirect precision
constraints. We further study the distinctive signatures of the predicted
non-standard Higgs bosons at the LHC. Finally, we analyze the direct detections
of GeV-scale mirror dark matter by TEXONO and CDEX experiments.Comment: 55pp. PRD final version. Only minor refinements (including to comment
on the latest LHC Higgs searches in Sec.5 and estimate abundances of mirror
dark matter particles in Sec.6); more references adde
Observation of the electromagnetic doubly OZI-suppressed decay
Using a sample of billion events accumulated with the BESIII
detector at the BEPCII collider, we report the observation of the decay , which is the first evidence for a doubly
Okubo-Zweig-Iizuka suppressed electromagnetic decay. A clear structure
is observed in the mass spectrum around 1.02 GeV/, which can
be attributed to interference between and
decays. Due to this interference, two
possible solutions are found. The corresponding measured values of the
branching fraction of are and .Comment: 7 pages, 4 figures, published in Phys. Rev.
Search for Gravitational Waves Associated with 39 Gamma-Ray Bursts Using Data from the Second, Third, and Fourth LIGO Runs
We present the results of a search for short-duration gravitational-wave
bursts associated with 39 gamma-ray bursts (GRBs) detected by gamma-ray
satellite experiments during LIGO's S2, S3, and S4 science runs. The search
involves calculating the crosscorrelation between two interferometer data
streams surrounding the GRB trigger time. We search for associated
gravitational radiation from single GRBs, and also apply statistical tests to
search for a gravitational-wave signature associated with the whole sample. For
the sample examined, we find no evidence for the association of gravitational
radiation with GRBs, either on a single-GRB basis or on a statistical basis.
Simulating gravitational-wave bursts with sine-gaussian waveforms, we set upper
limits on the root-sum-square of the gravitational-wave strain amplitude of
such waveforms at the times of the GRB triggers. We also demonstrate how a
sample of several GRBs can be used collectively to set constraints on
population models. The small number of GRBs and the significant change in
sensitivity of the detectors over the three runs, however, limits the
usefulness of a population study for the S2, S3, and S4 runs. Finally, we
discuss prospects for the search sensitivity for the ongoing S5 run, and beyond
for the next generation of detectors.Comment: 24 pages, 10 figures, 14 tables; minor changes to text and Fig. 2;
accepted by Phys. Rev.
Charlson comorbidity index helps predict the risk of mortality for patients with type 2 diabetic nephropathy
Aurora-A overexpression enhances cell-aggregation of Ha-ras transformants through the MEK/ERK signaling pathway
<p>Abstract</p> <p>Background</p> <p>Overexpression of Aurora-A and mutant Ras (Ras<sup>V12</sup>) together has been detected in human bladder cancer tissue. However, it is not clear whether this phenomenon is a general event or not. Although crosstalk between Aurora-A and Ras signaling pathways has been reported, the role of these two genes acting together in tumorigenesis remains unclear.</p> <p>Methods</p> <p>Real-time PCR and sequence analysis were utilized to identify Ha- and Ki-<it>ras </it>mutation (Gly -> Val). Immunohistochemistry staining was used to measure the level of Aurora-A expression in bladder and colon cancer specimens. To reveal the effect of overexpression of the above two genes on cellular responses, mouse NIH3T3 fibroblast derived cell lines over-expressing either Ras<sup>V12</sup>and wild-type Aurora-A (designated WT) or Ras<sup>V12 </sup>and kinase-inactivated Aurora-A (KD) were established. MTT and focus formation assays were conducted to measure proliferation rate and focus formation capability of the cells. Small interfering RNA, pharmacological inhibitors and dominant negative genes were used to dissect the signaling pathways involved.</p> <p>Results</p> <p>Overexpression of wild-type Aurora-A and mutation of Ras<sup>V12 </sup>were detected in human bladder and colon cancer tissues. Wild-type Aurora-A induces focus formation and aggregation of the Ras<sup>V12 </sup>transformants. Aurora-A activates Ral A and the phosphorylation of AKT as well as enhances the phosphorylation of MEK, ERK of WT cells. Finally, the Ras/MEK/ERK signaling pathway is responsible for Aurora-A induced aggregation of the Ras<sup>V12 </sup>transformants.</p> <p>Conclusion</p> <p>Wild-type-Aurora-A enhances focus formation and aggregation of the Ras<sup>V12 </sup>transformants and the latter occurs through modulating the Ras/MEK/ERK signaling pathway.</p
- …