135 research outputs found
Evidence for the suppression of intermediate anti-ferroelectric ordering and observation of hardening mechanism in Na1/2Bi 1/2TiO3 ceramics through cobalt substitution
Co-ion (5 mol %) substitution in Na1/2Bi1/2TiO 3 (NBT) host lattice and their effects on the structural, ferroelectric and dielectric behavior has been investigated thoroughly in this present study. The substituted Co-ion at Ti-site acts an acceptor type doping and hardens (i.e., increase in coercivity) the system without any noticeable change in the remanent polarization values. However, the intermediate antiferroelectric (AFE) ordering which exists between 200 C-280 C in NBT system has been suppressed due to Co-ion substitution, which is an interesting feature for device applications
Search for CP violation in decays
A model-independent search for direct CP violation in the Cabibbo suppressed
decay in a sample of approximately 370,000 decays is
carried out. The data were collected by the LHCb experiment in 2010 and
correspond to an integrated luminosity of 35 pb. The normalized Dalitz
plot distributions for and are compared using four different
binning schemes that are sensitive to different manifestations of CP violation.
No evidence for CP asymmetry is found.Comment: 13 pages, 8 figures, submitted to Phys. Rev.
Selumetinib in combination with dacarbazine in patients with metastatic uveal melanoma: a phase III, multicentre, randomised trial (SUMIT)
Purpose:
Uveal melanoma is the most common primary intraocular malignancy in adults with no effective
systemic treatment option in the metastatic setting. Selumetinib (AZD6244, ARRY-142886) is an
oral, potent, and selective MEK1/2 inhibitor with a short half-life, which demonstrated single-agent
activity in patients with metastatic uveal melanoma in a randomized phase II trial.
Methods:
The Selumetinib (AZD6244: ARRY-142886) (Hyd-Sulfate) in Metastatic Uveal Melanoma (SUMIT)
study was a phase III, double-blind trial (ClinicalTrial.gov identifier: NCT01974752) in which patients
with metastatic uveal melanoma and no prior systemic therapy were randomly assigned (3:1) to
selumetinib (75 mg twice daily) plus dacarbazine (1,000 mg/m2 intravenously on day 1 of every 21-
day cycle) or placebo plus dacarbazine. The primary end point was progression-free survival (PFS) by
blinded independent central radiologic review. Secondary end points included overall survival and
objective response rate.
Results:
A total of 129 patients were randomly assigned to receive selumetinib plus dacarbazine (n = 97) or
placebo plus dacarbazine (n = 32). In the selumetinib plus dacarbazine group, 82 patients (85%)
experienced a PFS event, compared with 24 (75%) in the placebo plus dacarbazine group (median,
2.8 v 1.8 months); the hazard ratio for PFS was 0.78 (95% CI, 0.48 to 1.27; two-sided P = .32). The
objective response rate was 3% with selumetinib plus dacarbazine and 0% with placebo plus
dacarbazine (two-sided P = .36). At 37% maturity (n = 48 deaths), analysis of overall survival gave
a hazard ratio of 0.75 (95% CI, 0.39 to 1.46; two-sided P = .40). The most frequently reported adverse
events (selumetinib plus dacarbazine v placebo plus dacarbazine) were nausea (62% v 19%), rash
(57% v 6%), fatigue (44% v 47%), diarrhea (44% v 22%), and peripheral edema (43% v 6%).
Conclusion:
In patients with metastatic uveal melanoma, the combination of selumetinib plus dacarbazine had
a tolerable safety profile but did not significantly improve PFS compared with placebo plus dacarbazine
First observation of Bs -> D_{s2}^{*+} X mu nu decays
Using data collected with the LHCb detector in proton-proton collisions at a
centre-of-mass energy of 7 TeV, the semileptonic decays Bs -> Ds+ X mu nu and
Bs -> D0 K+ X mu nu are detected. Two structures are observed in the D0 K+ mass
spectrum at masses consistent with the known D^+_{s1}(2536) and
$D^{*+}_{s2}(2573) mesons. The measured branching fractions relative to the
total Bs semileptonic rate are B(Bs -> D_{s2}^{*+} X mu nu)/B(Bs -> X mu nu)=
(3.3\pm 1.0\pm 0.4)%, and B(Bs -> D_{s1}^+ X munu)/B(Bs -> X mu nu)= (5.4\pm
1.2\pm 0.5)%, where the first uncertainty is statistical and the second is
systematic. This is the first observation of the D_{s2}^{*+} state in Bs
decays; we also measure its mass and width.Comment: 8 pages 2 figures. Published in Physics Letters
First observation of the decay and a measurement of the ratio of branching fractions
The first observation of the decay using
data collected by the LHCb detector at a centre-of-mass energy of 7 TeV,
corresponding to an integrated luminosity of 36 pb, is reported. A
signal of events is obtained and the absence of signal is
rejected with a statistical significance of more than nine standard deviations.
The branching fraction is measured relative to
that of : , where the first uncertainty is statistical, the second systematic and
the third is due to the uncertainty on the ratio of the and
hadronisation fractions.Comment: 10 pages, 3 figures, submitted to Phys. Lett. B; ISSN 0370-269
Essential Role of TGF-ÎČ/Smad Pathway on Statin Dependent Vascular Smooth Muscle Cell Regulation
BACKGROUND: The 3-hydroxy-3-methylglutaryl CoA reductase inhibitors (also called statins) exert proven beneficial effects on cardiovascular diseases. Recent data suggest a protective role for Transforming Growth Factor-beta (TGF-beta) in atherosclerosis by regulating the balance between inflammation and extracellular matrix accumulation. However, there are no studies about the effect of statins on TGF-beta/Smad pathway in atherosclerosis and vascular cells. METHODOLOGY: In cultured vascular smooth muscle cells (VSMCs) statins enhanced Smad pathway activation caused by TGF-beta. In addition, statins upregulated TGF-beta receptor type II (TRII), and increased TGF-beta synthesis and TGF-beta/Smad-dependent actions. In this sense, statins, through Smad activation, render VSMCs more susceptible to TGF-beta induced apoptosis and increased TGF-beta-mediated ECM production. It is well documented that high doses of statins induce apoptosis in cultured VSMC in the presence of serum; however the precise mechanism of this effect remains to be elucidated. We have found that statins-induced apoptosis was mediated by TGF-beta/Smad pathway. Finally, we have described that RhoA inhibition is a common intracellular mechanisms involved in statins effects. The in vivo relevance of these findings was assessed in an experimental model of atherosclerosis in apolipoprotein E deficient mice: Treatment with Atorvastatin increased Smad3 phosphorylation and TRII overexpression, associated to elevated ECM deposition in the VSMCs within atheroma plaques, while apoptosis was not detected. CONCLUSIONS: Statins enhance TGF-beta/Smad pathway, regulating ligand levels, receptor, main signaling pathway and cellular responses of VSMC, including apoptosis and ECM accumulation. Our findings show that TGF-beta/Smad pathway is essential for statins-dependent actions in VSMCs
Search for the lepton number violating decays and
A search is performed for the lepton number violating decay , where represents a or a , using data from the
LHCb detector corresponding to an integrated luminosity of . The
decay is forbidden in the Standard Model but allowed in models with a Majorana
neutrino. No signal is observed in either channel and limits of and are set at the 95% confidence level. These improve the
previous best limits by factors of 40 and 30, respectively
Measurement of b hadron production fractions in 7 TeV pp collisions
Measurements of hadron production ratios in proton-proton collisions at a
centre-of-mass energy of 7 TeV with an integrated luminosity of 3 pb are
presented. We study the ratios of strange meson to light meson
production and baryon to light meson
production as a function of the charmed hadron-muon
pair transverse momentum and the hadron pseudorapidity , for
between 0 and 14 GeV and between 2 and 5. We find that
is consistent with being independent of and ,
and we determine = 0.134 0.004 , where
the first error is statistical and the second systematic. The corresponding
ratio is found to be dependent upon the transverse
momentum of the charmed hadron-muon pair, , where Br reflects an absolute scale
uncertainty due to the poorly known branching fraction Br(\Lambda_c^+ \to
pK^-\pi^+)BBf_s/f_d\bar{B}_s \to
D_S^+ \pi ^-\bar{B}^0 \to D^+K^-\bar{B}^0 \to D^+\pi^-f_s/f_d=0.267^{+0.021}_{-0.020}$.Comment: 28 pages, 12 figures, version accepted for publication in Physical
Review D, few more detailed explanations on analysis methods adde
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