475 research outputs found
Factors predictive of lymph node metastasis in the follicular variant of papillary thyroid carcinoma
BACKGROUND: The treatment of papillary thyroid carcinomas larger than 1 cm usually consists of total thyroidectomy and central lymph node dissection (LND). In patients with the follicular variant of papillary thyroid carcinoma (FVPTC), preoperative cytology and intraoperative frozen-section analysis cannot always establish the diagnosis. The aim of this study was to evaluate predictive factors for lymph node metastasis in patients with FVPTC and to identify patients who might benefit from LND.
METHODS: The study included patients with FVPTC treated by total thyroidectomy and LND between 2000 and 2010 in four departments. When fewer than six non-involved lymph nodes were removed, the patient was excluded from the analysis.
RESULTS: Some 199 patients were included. The median tumour size was 17 (range 1-85) mm, and tumours were classified as T1a in 28 patients, T1b in 40, T2 in 53, and T3 in 78. Eighty-one patients (40·7 per cent) had lymph node metastasis (51 classified as N1a and 30 as N1b). Four risk factors were predictive of lymph node metastasis in the multivariable analysis: multifocality (odds ratio (OR) 2·36, 95 per cent confidence interval 1·15 to 4·86), angiolymphatic invasion (OR 3·67, 1·01 to 13·36), absence of tumour capsule (OR 3·00, 1·47 to 6·14) and tumour involvement of perithyroid tissue (OR 3·89, 1·85 to 8·18). The rate of lymph node metastasis varied between 14 and 94 per cent depending on the presence of risk factors.
CONCLUSION: The rate of lymph node metastasis in patients with FVPTC varies widely according to the presence or absence of predictive risk factors
Lemaitre-Tolman-Bondi model and accelerating expansion
I discuss the spherically symmetric but inhomogeneous Lemaitre-Tolman- Bondi
(LTB) metric, which provides an exact toy model for an inhomogeneous universe.
Since we observe light rays from the past light cone, not the expansion of the
universe, spatial variation in matter density and Hubble rate can have the same
effect on redshift as acceleration in a perfectly homogeneous universe. As a
consequence, a simple spatial variation in the Hubble rate can account for the
distant supernova data in a dust universe without any dark energy. I also
review various attempts towards a semirealistic description of the universe
based on the LTB model.Comment: Invited Review for a special Gen. Rel. Grav. issue on Dark Energy. 17
pages, 3 figure
Relic Neutrino Absorption Spectroscopy
Resonant annihilation of extremely high-energy cosmic neutrinos on big-bang
relic anti-neutrinos (and vice versa) into Z-bosons leads to sizable absorption
dips in the neutrino flux to be observed at Earth. The high-energy edges of
these dips are fixed, via the resonance energies, by the neutrino masses alone.
Their depths are determined by the cosmic neutrino background density, by the
cosmological parameters determining the expansion rate of the universe, and by
the large redshift history of the cosmic neutrino sources. We investigate the
possibility of determining the existence of the cosmic neutrino background
within the next decade from a measurement of these absorption dips in the
neutrino flux. As a by-product, we study the prospects to infer the absolute
neutrino mass scale. We find that, with the presently planned neutrino
detectors (ANITA, Auger, EUSO, OWL, RICE, and SalSA) operating in the relevant
energy regime above 10^{21} eV, relic neutrino absorption spectroscopy becomes
a realistic possibility. It requires, however, the existence of extremely
powerful neutrino sources, which should be opaque to nucleons and high-energy
photons to evade present constraints. Furthermore, the neutrino mass spectrum
must be quasi-degenerate to optimize the dip, which implies m_{nu} >~ 0.1 eV
for the lightest neutrino. With a second generation of neutrino detectors,
these demanding requirements can be relaxed considerably.Comment: 19 pages, 26 figures, REVTeX
Pembrolizumab as Consolidation Strategy in Patients with Multiple Myeloma: Results of the GEM-Pembresid Clinical Trial
PD1 expression in CD4+ and CD8+ T cells is increased after treatment in multiple myeloma patients with persistent disease. The GEM-Pembresid trial analyzed the efficacy and safety of pembrolizumab as consolidation in patients achieving at least very good partial response but with persistent measurable disease after first- or second-line treatment. Moreover, the characteristics of the immune system were investigated to identify potential biomarkers of response to pembrolizumab. One out of the 17 evaluable patients showed a decrease in the amount of M-protein, although a potential late effect of high-dose melphalan could not be ruled out. Fourteen adverse events were considered related to pembrolizumab, two of which (G3 diarrhea and G2 pneumonitis) prompted treatment discontinuation and all resolving without sequelae. Interestingly, pembrolizumab induced a decrease in the percentage of NK cells at cycle 3, due to the reduction of the circulating and adaptive subsets (0.615 vs. 0.43, p = 0.007; 1.12 vs. 0.86, p = 0.02). In the early progressors, a significantly lower expression of PD1 in CD8+ effector memory T cells (MFI 1327 vs. 926, p = 0.03) was observed. In conclusion, pembrolizumab used as consolidation monotherapy shows an acceptable toxicity profile but did not improve responses in this MM patient population. The trial was registered at clinicaltrials.gov with identifier NCT02636010 and with EUDRACT number 2015-003359-23.This study was funded by FundaciĂłn RamĂłn Areces (FRA 16/003). T.P. is supported by a grant from the AECC (INVES18043PAIN). This study received financial support from Merck Sharp & Dohme of Spain, a subsidiary of Merck & Co., Inc., Whitehouse Station, New Jersey, USA
Susceptibility and dilution effects of the kagome bi-layer geometrically frustrated network. A Ga-NMR study of SrCr_(9p)Ga_(12-9p)O_(19)
We present an extensive gallium NMR study of the geometrically frustrated
kagome bi-layer compound SrCr_(9p)Ga_(12-9p)O_(19) (Cr^3+, S=3/2) over a broad
Cr-concentration range (.72<p<.95). This allows us to probe locally the kagome
bi-layer susceptibility and separate the intrinsic properties due to the
geometric frustration from those related to the site dilution. Our major
findings are: 1) The intrinsic kagome bi-layer susceptibility exhibits a
maximum in temperature at 40-50 K and is robust to a dilution as high as ~20%.
The maximum reveals the development of short range antiferromagnetic
correlations; 2) At low-T, a highly dynamical state induces a strong wipe-out
of the NMR intensity, regardless of dilution; 3) The low-T upturn observed in
the macroscopic susceptibility is associated to paramagnetic defects which stem
from the dilution of the kagome bi-layer. The low-T analysis of the NMR
lineshape suggests that the defect can be associated with a staggered
spin-response to the vacancies on the kagome bi-layer. This, altogether with
the maximum in the kagome bi-layer susceptibility, is very similar to what is
observed in most low-dimensional antiferromagnetic correlated systems; 4) The
spin glass-like freezing observed at T_g=2-4 K is not driven by the
dilution-induced defects.Comment: 19 pages, 19 figures, revised version resubmitted to PRB Minor
modifications: Fig.11 and discussion in Sec.V on the NMR shif
Pembrolizumab as consolidation strategy in patients with multiple myeloma: Results of the GEM-Pembresid clinical trial
PD1 expression in CD4+ and CD8+ T cells is increased after treatment in multiple myeloma
patients with persistent disease. The GEM-Pembresid trial analyzed the efficacy and safety of
pembrolizumab as consolidation in patients achieving at least very good partial response but with
persistent measurable disease after first- or second-line treatment. Moreover, the characteristics of the
immune system were investigated to identify potential biomarkers of response to pembrolizumab.
One out of the 17 evaluable patients showed a decrease in the amount of M-protein, although a
potential late effect of high-dose melphalan could not be ruled out. Fourteen adverse events were
considered related to pembrolizumab, two of which (G3 diarrhea and G2 pneumonitis) prompted
treatment discontinuation and all resolving without sequelae. Interestingly, pembrolizumab induced
a decrease in the percentage of NK cells at cycle 3, due to the reduction of the circulating and adaptive
subsets (0.615 vs. 0.43, p = 0.007; 1.12 vs. 0.86, p = 0.02). In the early progressors, a significantly
lower expression of PD1 in CD8+ effector memory T cells (MFI 1327 vs. 926, p = 0.03) was observed.
In conclusion, pembrolizumab used as consolidation monotherapy shows an acceptable toxicity
profile but did not improve responses in this MM patient population. The trial was registered at
clinicaltrials.gov with identifier NCT02636010 and with EUDRACT number 2015-003359-23
Search for direct production of charginos and neutralinos in events with three leptons and missing transverse momentum in âs = 7 TeV pp collisions with the ATLAS detector
A search for the direct production of charginos and neutralinos in final states with three electrons or muons and missing transverse momentum is presented. The analysis is based on 4.7 fbâ1 of protonâproton collision data delivered by the Large Hadron Collider and recorded with the ATLAS detector. Observations are consistent with Standard Model expectations in three signal regions that are either depleted or enriched in Z-boson decays. Upper limits at 95% confidence level are set in R-parity conserving phenomenological minimal supersymmetric models and in simplified models, significantly extending previous results
Jet size dependence of single jet suppression in lead-lead collisions at sqrt(s(NN)) = 2.76 TeV with the ATLAS detector at the LHC
Measurements of inclusive jet suppression in heavy ion collisions at the LHC
provide direct sensitivity to the physics of jet quenching. In a sample of
lead-lead collisions at sqrt(s) = 2.76 TeV corresponding to an integrated
luminosity of approximately 7 inverse microbarns, ATLAS has measured jets with
a calorimeter over the pseudorapidity interval |eta| < 2.1 and over the
transverse momentum range 38 < pT < 210 GeV. Jets were reconstructed using the
anti-kt algorithm with values for the distance parameter that determines the
nominal jet radius of R = 0.2, 0.3, 0.4 and 0.5. The centrality dependence of
the jet yield is characterized by the jet "central-to-peripheral ratio," Rcp.
Jet production is found to be suppressed by approximately a factor of two in
the 10% most central collisions relative to peripheral collisions. Rcp varies
smoothly with centrality as characterized by the number of participating
nucleons. The observed suppression is only weakly dependent on jet radius and
transverse momentum. These results provide the first direct measurement of
inclusive jet suppression in heavy ion collisions and complement previous
measurements of dijet transverse energy imbalance at the LHC.Comment: 15 pages plus author list (30 pages total), 8 figures, 2 tables,
submitted to Physics Letters B. All figures including auxiliary figures are
available at
http://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/HION-2011-02
Measurement of the polarisation of W bosons produced with large transverse momentum in pp collisions at sqrt(s) = 7 TeV with the ATLAS experiment
This paper describes an analysis of the angular distribution of W->enu and
W->munu decays, using data from pp collisions at sqrt(s) = 7 TeV recorded with
the ATLAS detector at the LHC in 2010, corresponding to an integrated
luminosity of about 35 pb^-1. Using the decay lepton transverse momentum and
the missing transverse energy, the W decay angular distribution projected onto
the transverse plane is obtained and analysed in terms of helicity fractions
f0, fL and fR over two ranges of W transverse momentum (ptw): 35 < ptw < 50 GeV
and ptw > 50 GeV. Good agreement is found with theoretical predictions. For ptw
> 50 GeV, the values of f0 and fL-fR, averaged over charge and lepton flavour,
are measured to be : f0 = 0.127 +/- 0.030 +/- 0.108 and fL-fR = 0.252 +/- 0.017
+/- 0.030, where the first uncertainties are statistical, and the second
include all systematic effects.Comment: 19 pages plus author list (34 pages total), 9 figures, 11 tables,
revised author list, matches European Journal of Physics C versio
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