1,761 research outputs found
SUSY Contributions to and Top Decay
I report on a systematic analysis of the MSSM parameter space to obtain the
best SUSY solution to the anomaly within the constraint of top quark
decay. Phenomenological implications for top decay and direct stop production
at the Tevatron collider are discussed.Comment: Latex file (3 pages)+ 2 ps files containing figures. Invited talk at
SUSY96, Maryland, May 199
Prevalence of baseline polymorphisms for potential resistance to NS5A inhibitors in drug-naive individuals infected with hepatitis C genotypes 1–4
Background: The non-structural 5A (NS5A) protein of HCV is a multifunctional phosphoprotein involved in regulation of viral replication and virion assembly. NS5A inhibitors targeting domain I of NS5A protein have demonstrated high potency and pan-genotypic antiviral activity, however they possess a low genetic barrier to resistance. At present, only genotype 1, the most prevalent HCV genotype has been studied in detail for resistant variants.
Methods: Utilising a panel of genotypic-specific resistance assays, population sequencing was performed on plasma derived viral RNA isolated from 138 patients infected with HCV genotypes 1-4 and not treated with directly acting anti-viral agents (DAAs). Amino acid changes in HCV NS5A domain I at codon positions 28, 30, 31, 32 and 93, reported to confer reduced susceptibility to certain NS5A inhibitors were examined. Additionally, genotypic outcome based on NS5A sequences were compared with LiPA and Abbott® real time.
Results: Amino acid substitutions associated with moderate to high level resistance to NS5A inhibitors were detected in 2/42 (4.76%) HCV-1a, 3/23 (13.04%) HCV-1b, 4/26 ( 15.38% ) HCV-2, 1/24 (4.17%) HCV-3 and 1/23 (4.35%) HCV-4 infected patients who had not been treated with NS5A inhibitors. Genotype prediction based on NS5A sequences were concordant with LiPA and/or Abbott® real-time for 97.10% of cases.
Conclusion: Primary resistance mutations associated with resistance to first generation NS5A inhibitors such as Daclatasvir (DCV) were observed in all genotypes, albeit at low frequencies. An excellent correlation based on NS5A genotyping and LiPA or Abbott® real-time was achieved
Limits on Associated Production of Visibly and Invisibly Decaying Higgs Bosons from Z Decays
Many extensions of the standard electroweak model Higgs sector suggest that
the main Higgs decay channel is "invisible", for example, where
denotes the majoron, a weakly interacting pseudoscalar Goldstone boson
associated to the spontaneous violation of lepton number. In many of these
models the Higgs boson may also be produced in association to a massive
pseudoscalar boson (HA), in addition to the standard Bjorken mechanism (HZ). We
describe a general strategy to determine limits from LEP data on the masses and
couplings of such Higgs bosons, using the existing data on acoplanar dijet
events as well as data on four and six jet event topologies. For the sake
of illustration, we present constraints that can be obtained for the ALEPH
data.Comment: FTUV/94-36, IFIC/94-31 TIFR/TH/94--25, 12 pages + 4 figures (included
as ps files at the end
Constraints on the Charged Higgs Sector from the Tevatron Collider Data on Top Quark Decay
The top quark data in the lepton plus channel offers a viable probe
for the charged Higgs boson signal. We analyse the recent Tevatron collider
data in this channel to obtain a significant limit on the mass in the
large region.Comment: 8 pages, LaTeX file; 2 figures included (PS files
Constraints on neutrino oscillation parameters from the SNO salt phase data
The physics implications of the just published salt phase data from the SNO
experiment are examined. The effect of these data on the allowed ranges of the
solar neutrino oscillation parameters, \Delta_m^2_{21} and
, are studied in the cases of two- and three- neutrino
mixing. In the latter case we derive an upper limit on the angle .
Constraints on the solar transitions into a mixture of active and
sterile neutrinos are also presented. Finally, we give predictions for the
day-night asymmetry in the SNO experiment, for the event rate in the BOREXINO
and LowNu experiments, and discuss briefly the constraints on the solar
neutrino oscillation parameters which can be obtained with prospective KamLAND
data.Comment: Version to appear in PL
The Solar Neutrino Problem after the first results from Kamland
The first results from the KamLAND experiment have provided confirmational
evidence for the Large Mixing Angle (LMA) MSW solution to the solar neutrino
problem. We do a global analysis of solar and the recently announced KamLAND
data (both rate and spectrum) and investigate its effect on the allowed region
in the plane. The best-fit from a combined analysis
which uses the KamLAND rate plus global solar data comes at eV and , very close to the global solar
best-fit, leaving a large allowed region within the global solar LMA contour.
The inclusion of the KamLAND spectral data in the global fit gives a best-fit
eV and and
constrains the allowed areas within LMA, leaving essentially two allowed zones.
Maximal mixing though allowed by the KamLAND data alone is disfavored by the
global solar data and remains disallowed at about . The LOW solution
is now ruled out at about 5 w.r.t. the LMA solution.Comment: Version to appear in PL
Rolling Tachyon in Brane World Cosmology from Superstring Field Theory
The pressureless tachyonic matter recently found in superstring field theory
has an over-abundance problem in cosmology. We argue that this problem is
naturally solved in the brane inflationary scenario if almost all of the
tachyon energy is drained (via its coupling to the inflaton and matter fields)
to heating the universe, while the rest of the tachyon energy goes to a network
of cosmic strings (lower-dimensional BPS D-branes) produced during the tachyon
rolling at the end of inflation.Comment: 4 pages, one figure. This version quantifies constraints on various
phenomenological models for tachyon deca
Low molecular weight heparin (reviparin) in percutaneous transluminal coronary angioplasty. Results of a randomized, double-blind, unfractionated heparin and placebo-controlled, multicenter trial (REDUCE trial)
Objectives. The specific objective of the REDUCE trial was to evaluate the effect of low molecular weight heparin on the incidence and occurrence of restenosis in patients undergoing percutaneous transluminal coronary angioplasty (PTCA). Background. Unfractionated heparin and its low molecular weight fragments possess antiproliferative effects and have been shown to reduce neointimal smooth muscle cell migration and proliferation in response to vascular injury in experimental studies. Methods. The REDUCE trial is an international prospective, randomized, double-blind, multicenter study. Twenty-six centers in Europe and Canada enrolled 625 patients with single-lesion coronary artery obstructions suitable for PTCA. Three hundred six patients received reviparin as a 7,000-U bolus before PTCA, followed by 10,500 U as an infusion over 24 h and then twice-daily 3,500-U subcutaneous application for 28 days. The 306 patients in the control group received a bolus of 10,000 U o
The alpha-galactosidase A p.Arg118Cys variant does not cause a Fabry disease phenotype: data from individual patients and family studies
Acessível em: www.ncbi.nlm.nih.gov/pmc/articles/PMC4423738/Lysosomal α-galactosidase A (α-Gal) is the enzyme deficient in Fabry disease (FD), an X-linked glycosphingolipidosis caused by pathogenic mutations affecting the GLA gene. The early-onset, multi-systemic FD classical phenotype is associated with absent or severe enzyme deficiency, as measured by in vitro assays, but patients with higher levels of residual α-Gal activity may have later-onset, more organ-restricted clinical presentations. A change in the codon 118 of the wild-type α-Gal sequence, replacing basic arginine by a potentially sulfhydryl-binding cysteine residue - GLA p.(Arg118Cys) -, has been recurrently described in large FD screening studies of high-risk patients. Although the Cys118 allele is associated with high residual α-Gal activity in vitro, it has been classified as a pathogenic mutation, mainly on the basis of theoretical arguments about the chemistry of the cysteine residue. However its pathogenicity has never been convincingly demonstrated by pathology criteria. We reviewed the clinical, biochemical and histopathology data obtained from 22 individuals of Portuguese and Spanish ancestry carrying the Cys118 allele, including 3 homozygous females. Cases were identified either on the differential diagnosis of possible FD manifestations and on case-finding studies (n=11; 4 males), or on unbiased cascade screening of probands' close relatives (n=11; 3 males). Overall, those data strongly suggest that the GLA p.(Arg118Cys) variant does not segregate with FD clinical phenotypes in a Mendelian fashion, but might be a modulator of the multifactorial risk of cerebrovascular disease. The Cys118 allelic frequency in healthy Portuguese adults (n=696) has been estimated as 0.001, therefore not qualifying for "rare" condition
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