677 research outputs found
Associating Liver Partition and Portal Vein Ligation for Staged Hepatectomy (ALPPS) procedure for colorectal liver metastasis
Since first described, Associating Liver Partition and Portal Vein Ligation for Staged Hepatectomy (ALPPS) has garnered boisterous praise and fervent criticism. Its rapid adoption and employment for a variety of indications resulted in high perioperative morbidity and mortality. However recent risk stratification, refinement of technique to reduce the impact of stage I and progression along the learning curve have resulted in improved outcomes. The first randomized trial comparing ALPPS to two stage hepatectomy (TSH) for colorectal liver metastases (CRLM) was recently published demonstrating comparable perioperative morbidity and mortality with improved resectability and survival following ALPPS. In this review, as ALPPS enters the thirteenth year since conception, the current status of this contentious two stage technique is presented and best practices for deployment in the treatment of CRLM is codified
A Generalized Diffusion Tensor for Fully Anisotropic Diffusion of Energetic Particles in the Heliospheric Magnetic Field
The spatial diffusion of cosmic rays in turbulent magnetic fields can, in the
most general case, be fully anisotropic, i.e. one has to distinguish three
diffusion axes in a local, field-aligned frame. We reexamine the transformation
for the diffusion tensor from this local to a global frame, in which the Parker
transport equation for energetic particles is usually formulated and solved.
Particularly, we generalize the transformation formulas to allow for an
explicit choice of two principal local perpendicular diffusion axes. This
generalization includes the 'traditional' diffusion tensor in the special case
of isotropic perpendicular diffusion. For the local frame, we motivate the
choice of the Frenet-Serret trihedron which is related to the intrinsic
magnetic field geometry. We directly compare the old and the new tensor
elements for two heliospheric magnetic field configurations, namely the hybrid
Fisk and the Parker field. Subsequently, we examine the significance of the
different formulations for the diffusion tensor in a standard 3D model for the
modulation of galactic protons. For this we utilize a numerical code to
evaluate a system of stochastic differential equations equivalent to the Parker
transport equation and present the resulting modulated spectra. The computed
differential fluxes based on the new tensor formulation deviate from those
obtained with the 'traditional' one (only valid for isotropic perpendicular
diffusion) by up to 60% for energies below a few hundred MeV depending on
heliocentric distance.Comment: 8 pages, 6 figures, accepted in Ap
Antioxidative potential of a combined therapy of anti TNFα and Zn acetate in experimental colitis.
AIM: To evaluate whether combination therapy with anti-tumour necrosis factor α
(TNFα) antibody and Zn acetate is beneficial in dextran sodium sulphate (DSS)
colitis.
METHODS: Colitis was induced in CD1-Swiss mice with 5% DSS for 7 d. The
experimental mice were then randomised into the following subgroups: standard
diet + DSS treated (induced colitis group); standard diet + DSS + subcutaneous 25
μg anti-TNFα treated group; Zn acetate treated group + DSS + subcutaneous 25 μg
anti-TNFα; standard diet + DSS + subcutaneous 6.25 μg anti-TNFα treated group and
Zn acetate treated group + DSS + subcutaneous 6.25 μg anti-TNFα. Each group of
mice was matched with a similar group of sham control animals. Macroscopic and
histological features were scored blindly. Homogenates of the colonic mucosa were
assessed for myeloperoxidase activity as a biochemical marker of inflammation and
DNA adducts (8OH-dG) as a measure of oxidative damage.
RESULTS: DSS produced submucosal erosions, ulcers, inflammatory cell infiltration
and cryptic abscesses which were reduced in both groups of mice receiving either
anti-TNFα alone or combined with zinc. The effect was more pronounced in the
latter group (vs Zn diet, P < 0.02). Myeloperoxidase activity (vs controls, P <
0.02) and DNA adducts, greatly elevated in the DSS fed colitis group (vs
controls, P < 0.05), were significantly reduced in the treated groups, with a
more remarkable effect in the group receiving combined therapy (vs standard diet,
P < 0.04).
CONCLUSION: DSS induces colonic inflammation which is modulated by the
administration of anti-TNFα. Combining anti-TNFα with Zn acetate offers marginal
benefit in colitis severity
Endothelin receptors (version 2019.4) in the IUPHAR/BPS Guide to Pharmacology Database
Endothelin receptors (nomenclature as agreed by the NC-IUPHAR Subcommittee on Endothelin Receptors [24]) are activated by the endogenous 21 amino-acid peptides endothelins 1-3 (endothelin-1, endothelin-2 and endothelin-3)
Endothelin receptors in GtoPdb v.2023.1
Endothelin receptors (nomenclature as agreed by the NC-IUPHAR Subcommittee on Endothelin Receptors [24]) are activated by the endogenous 21 amino-acid peptides endothelins 1-3 (endothelin-1, endothelin-2 and endothelin-3)
Kolmogorov-Sinai entropy in field line diffusion by anisotropic magnetic turbulence
The Kolmogorov-Sinai (KS) entropy in turbulent diffusion of magnetic field
lines is analyzed on the basis of a numerical simulation model and theoretical
investigations. In the parameter range of strongly anisotropic magnetic
turbulence the KS entropy is shown to deviate considerably from the earlier
predicted scaling relations [Rev. Mod. Phys. {\bf 64}, 961 (1992)]. In
particular, a slowing down logarithmic behavior versus the so-called Kubo
number (, where is the ratio of the rms magnetic fluctuation field to the magnetic field
strength, and and are the correlation lengths in respective
dimensions) is found instead of a power-law dependence. These discrepancies are
explained from general principles of Hamiltonian dynamics. We discuss the
implication of Hamiltonian properties in governing the paradigmatic
"percolation" transport, characterized by , associating it with the
concept of pseudochaos (random non-chaotic dynamics with zero Lyapunov
exponents). Applications of this study pertain to both fusion and astrophysical
plasma and by mathematical analogy to problems outside the plasma physics.
This research article is dedicated to the memory of Professor George M.
ZaslavskyComment: 15 pages, 2 figures. Accepted for publication on Plasma Physics and
Controlled Fusio
Coronary Thrombolysis with Intravenous Streptokinase in the Anesthetized Dog: A Dose-Response Study
ABSTRAC
Muon excess at sea level from solar flares in association with the Fermi GBM spacecraft detector
This paper presents results of an ongoing survey on the associations between
muon excesses at ground level registered by the Tupi telescopes and transient
solar events, two solar flares whose gamma-ray and X-ray emissions were
reported by, respectively, the Fermi GBM and the GOES 14. We show that solar
flares of small scale, those with prompt X-ray emission classified by GOES as
C-Class (power to W m at 1 AU) may give rise to muon
excess probably associated with solar protons and ions emitted by the flare and
arriving at the Earth as a coherent particle pulse. The Tupi telescopes are
within the central region of the South Atlantic Anomaly (SAA), which allows
particle detectors to achieve a low rigidity of response to primary and
secondary charged particles ( GV). Here we argue for the possibility
of a "scale-free" energy distribution of particles accelerated by solar flares.
Large and small scale flares have the same energy spectrum up to energies
exceeding the pion production, the difference between them is only the
intensity. If this hypothesis is correct, the Tupi telescope is registering
muons produced by protons (ions) whose energy corresponds to the tail of the
spectrum. Consequently the energy distribution of the emitted protons has to be
a power law spectrum, since power law distributions are characterized as scale
free distributions. The Tupi events give support to this conjecture.Comment: 24 pages, 10 figure
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