235 research outputs found
Reduction in the structural changes of experimental osteoarthritis by a nitric oxide inhibitor
AbstractObjectiveTo evaluate the in-vivo therapeutic efficacy ofN-iminoethyl-L-Lysine (L-NIL), a selective inhibitor of inducible nitric oxide synthase (iNOS) in a dose response study, on the progression of lesions in the experimental osteoarthritic (OA) dog model.DesignThe sectioning of the anterior cruciate ligament of the right stifle joint of mongrel dogs was done by a stab wound. Dogs were separated into experimental groups: Group 1 received no treatment, Groups 2, 3, and 4 received oral L-NIL (0.3, 1 or 10mg/kg/day, respectively) starting immediately after surgery. The OA dogs were killed at 12 weeks after surgery.ResultsMacroscopically, L-NIL decreased the size of the cartilage lesions on condyles and plateaus. The histologic severity of the cartilage lesions was decreased in the L-NIL-treated dogs. This effect was more pronounced at the highest dosage tested (3 and 10mg/kg/day).ConclusionsThis study confirms the effectiveness of L-NIL, a selective inhibitor of iNOS, in attenuating the progression of experimental OA. It also clearly shows that the effect is dose-dependent
Improved modelling of helium and tritium production for spallation targets
Reliable predictions of light charged particle production in spallation
reactions are important to correctly assess gas production in spallation
targets. In particular, the helium production yield is important for assessing
damage in the window separating the accelerator vacuum from a spallation
target, and tritium is a major contributor to the target radioactivity. Up to
now, the models available in the MCNPX transport code, including the widely
used default option Bertini-Dresner and the INCL4.2-ABLA combination of models,
were not able to correctly predict light charged particle yields. The work done
recently on both the intranuclear cascade model INCL4, in which cluster
emission through a coalescence process has been introduced, and on the
de-excitation model ABLA allows correcting these deficiencies. This paper shows
that the coalescence emission plays an important role in the tritium and
production and that the combination of the newly developed versions of the
codes, INCL4.5-ABLA07, now lead to good predictions of both helium and tritium
cross sections over a wide incident energy range. Comparisons with other
available models are also presented.Comment: 6 pages, 9 figure
The JCMT Gould Belt survey: Dense core clusters in Orion B
The James Clerk Maxwell Telescope Gould Belt Legacy Survey obtained SCUBA-2 observations of dense cores within three sub-regions of OrionB: LDN1622, NGC2023/2024, and NGC2068/2071, all of which contain clusters of cores. We present an analysis of the clustering properties of these cores, including the two-point correlation function and Cartwright’s Q parameter. We identify individual clusters of dense cores across all three regions using a minimal spanning tree technique, and find that in each cluster, the most massive cores tend to be centrally located. We also apply the independent M–Σ technique and find a strong correlation between core mass and the local surface density of cores. These two lines of evidence jointly suggest that some amount of mass segregation in clusters has happened already at the dense core stage
The risk of cardiac failure following metal-on-metal hip arthroplasty
Aims
The aim of this study was to determine whether patients with metal-on-metal (MoM)
arthroplasties of the hip have an increased risk of cardiac failure compared with those with
alternative types of arthroplasties (non-MoM).
Patients and Methods
A linkage study between the National Joint Registry, Hospital Episodes Statistics and records
of the Office for National Statistics on deaths was undertaken. Patients who underwent
elective total hip arthroplasty between January 2003 and December 2014 with no past history
of cardiac failure were included and stratified as having either a MoM (n = 53 529) or a nonMoM
(n = 482 247) arthroplasty. The primary outcome measure was the time to an
admission to hospital for cardiac failure or death. Analysis was carried out using data from
all patients and from those matched by propensity score.
Results
The risk of cardiac failure was lower in the MoM cohort compared with the non-MoM cohort
(adjusted hazard ratio (aHR) 0.901; 95% confidence interval (CI) 0.853 to 0.953). The risk of
cardiac failure was similar following matching (aHR 0.909; 95% CI 0.838 to 0.987) and the
findings were consistent in subgroup analysis.
Conclusion
The risk of cardiac failure following total hip arthroplasty was not increased in those in
whom MoM implants were used, compared with those in whom other types of prostheses
were used, in the first seven years after surgery.
Cite this article: Bone Joint J 2018;100-B:20–
Kinks in the Hartree approximation
The topological defects of the lambda phi^4 theory, kink and antikink, are
studied in the Hartree approximation. This allows us to discuss quantum effects
on the defects in both stationary and dynamical systems. The kink mass is
calculated for a number of parameters, and compared to classical, one loop and
Monte Carlo results known from the literature. We discuss the thermalization of
the system after a kink antikink collision. A classical result, the existence
of a critical speed, is rederived and shown for the first time in the quantum
theory. We also use kink antikink collisions as a very simple toy model for
heavy ion collisions and discuss the differences and similarities, for example
in the pressure. Finally, using the Hartree Ensemble Approximation allows us to
study kink antikink nucleation starting from a thermal (Bose Einstein)
distribution. In general our results indicate that on a qualitative level there
are few differences with the classical results, but on a quantitative level
there are some import ones.Comment: 20 pages REVTeX 4, 17 Figures. Uses amsmath.sty and subfigure.sty.
Final version, fixed typo in published versio
High-contrast imaging constraints on gas giant planet formation - The Herbig Ae/Be star opportunity
Planet formation studies are often focused on solar-type stars, implicitly
considering our Sun as reference point. This approach overlooks, however, that
Herbig Ae/Be stars are in some sense much better targets to study planet
formation processes empirically, with their disks generally being larger,
brighter and simply easier to observe across a large wavelength range. In
addition, massive gas giant planets have been found on wide orbits around early
type stars, triggering the question if these objects did indeed form there and,
if so, by what process. In the following I briefly review what we currently
know about the occurrence rate of planets around intermediate mass stars,
before discussing recent results from Herbig Ae/Be stars in the context of
planet formation. The main emphasis is put on spatially resolved polarized
light images of potentially planet forming disks and how these images - in
combination with other data - can be used to empirically constrain (parts of)
the planet formation process. Of particular interest are two objects, HD100546
and HD169142, where, in addition to intriguing morphological structures in the
disks, direct observational evidence for (very) young planets has been
reported. I conclude with an outlook, what further progress we can expect in
the very near future with the next generation of high-contrast imagers at 8-m
class telescopes and their synergies with ALMA.Comment: Accepted by Astrophysics and Space Science as invited short review in
special issue about Herbig Ae/Be stars; 12 pages incl. 5 figures, 2 tables
and reference
Upstream Solutions: Does the Supplemental Security Income Program Reduce Disability in the Elderly?
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/72843/1/j.1468-0009.2007.00512.x.pd
Predation rate of Spodoptera frugiperda (Lepidoptera: Noctuidae) larvae with and without defense by Podisus nigrispinus (Heteroptera: Pentatomidae)
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