937 research outputs found
Numerically Computing QCD Laplace Sum-Rules Using pySecDec
pySecDec is a program that numerically calculates dimensionally regularized
integrals. We use pySecDec to compute QCD Laplace sum-rules for pseudoscalar
(i.e., ) charmonium hybrids, and compare the results to
sum-rules computed using analytic results for dimensionally regularized
integrals. We find that the errors due to the use of numerical integration
methods is negligible compared to the uncertainties in the sum-rules stemming
from the uncertainties in the parameters of QCD, e.g., the coupling constant,
quark masses, and condensate values. Also, we demonstrate that numerical
integration methods can be used to calculate finite-energy and Gaussian
sum-rules in addition to Laplace sum-rules.Comment: 10 pages, 5 figure
Drug-like analogues of the parasitic worm-derived immunomodulator ES-62 are therapeutic in the MRL/Lpr model of systemic lupus erythematosus
Introduction ES-62, a phosphorylcholine (PC)-containing immunomodulator secreted by the parasitic worm Acanthocheilonema viteae, protects against nephritis in the MRL/Lpr mouse model of systemic lupus erythematosus (SLE). However, ES-62 is not suitable for development as a therapy and thus we have designed drug-like small molecule analogues (SMAs) based around its active PC-moiety. To provide proof of concept that ES-62-based SMAs exhibit therapeutic potential in SLE, we have investigated the capacity of two SMAs to protect against nephritis when administered to MRL/Lpr mice after onset of kidney damage.
Methods SMAs 11a and 12b were evaluated for their ability to suppress antinuclear antibody (ANA) generation and consequent kidney pathology in MRL/Lpr mice when administered after the onset of proteinuria.
Results SMAs 11a and 12b suppressed development of ANA and proteinuria. Protection reflected downregulation of MyD88 expression by kidney cells and this was associated with reduced production of IL-6, a cytokine that exhibits promise as a therapeutic target for this condition.
Conclusions SMAs 11a and 12b provide proof of principle that synthetic compounds based on the safe immunomodulatory mechanisms of parasitic worms can exhibit therapeutic potential as a novel class of drugs for SLE, a disease for which current therapies remain inadequate
Gaussian Sum-Rule Analysis of Scalar Gluonium and Quark Mesons
Gaussian sum-rules, which are related to a two-parameter Gaussian-weighted
integral of a hadronic spectral function, are able to examine the possibility
that more than one resonance makes a significant contribution to the spectral
function. The Gaussian sum-rules, including instanton effects, for scalar
gluonic and non-strange scalar quark currents clearly indicate a distribution
of the resonance strength in their respective spectral functions. Furthermore,
analysis of a two narrow resonance model leads to excellent agreement between
theory and phenomenology in both channels. The scalar quark and gluonic
sum-rules are remarkably consistent in their prediction of masses of
approximately 1.0 GeV and 1.4 GeV within this model. Such a similarity would be
expected from hadronic states which are mixtures of gluonium and quark mesons.Comment: latex2e using amsmath, 11 pages, 4 eps figures embedded in latex
file. Write-up of presentation for the 2003 SUNY IT (Utica) workshop on
scalar meson
Masses of Open-Flavour Heavy-Light Hybrids from QCD Sum-Rules
We use QCD Laplace sum-rules to predict masses of open-flavour heavy-light
hybrids where one of the hybrid's constituent quarks is a charm or bottom and
the other is an up, down, or strange. We compute leading-order, diagonal
correlation functions of several hybrid interpolating currents, taking into
account QCD condensates up to dimension-six, and extract hybrid mass
predictions for all , as well as explore possible
mixing effects with conventional quark-antiquark mesons. Within theoretical
uncertainties, our results are consistent with a degeneracy between the
heavy-nonstrange and heavy-strange hybrids in all channels. We find a
similar mass hierarchy of , , and states (a state
lighter than essentially degenerate and states) in both the
charm and bottom sectors, and discuss an interpretation for the states.
If conventional meson mixing is present the effect is an increase in the hybrid
mass prediction, and we estimate an upper bound on this effect.Comment: 24 pages, 8 figures. Mass predictions updated from previous version
to reflect corrected sign error in sum rule analysis. Mixing analysis and
examination of higher weight sum-rules added. To be published in JHE
The parasitic worm-derived immunomodulator, ES-62 and its drug-like small molecule analogues exhibit therapeutic potential in a model of chronic asthma
Chronic asthma is associated with persistent lung inflammation and long-term remodelling of the airways that have proved refractory to conventional treatments such as steroids, despite their efficacy in controlling acute airway contraction and bronchial inflammation. As its recent dramatic increase in industrialised countries has not been mirrored in developing regions, it has been suggested that helminth infection may protect humans against developing asthma. Consistent with this, ES-62, an immunomodulator secreted by the parasitic worm Acanthocheilonema viteae, can prevent pathology associated with chronic asthma (cellular infiltration of the lungs, particularly neutrophils and mast cells, mucus hyper-production and airway thickening) in an experimental mouse model. Importantly, ES-62 can act even after airway remodelling has been established, arresting pathogenesis and ameliorating the inflammatory flares resulting from repeated exposure to allergen that are a debilitating feature of severe chronic asthma. Moreover, two chemical analogues of ES-62, 11a and 12b mimic its therapeutic actions in restoring levels of regulatory B cells and suppressing neutrophil and mast cell responses. These studies therefore provide a platform for developing ES-62-based drugs, with compounds 11a and 12b representing the first step in the development of a novel class of drugs to combat the hitherto intractable disorder of chronic asthma
- …