CAROTID endarterectomy was introduced in 1954 as a logical procedure for the prevention of ischemic stroke distal to carotid-artery stenosis.
1
Although the first randomized trials of its ...effectiveness had negative results,
2
3
4
surgeons continued to perform carotid endarterectomy and began to report lower rates of perioperative complications.
5
,
6
The number of patients undergoing endarterectomy in hospitals in the United States (other than Veterans Affairs hospitals) rose from 15,000 in 1971 to 107,000 in 1985.
7
However, continuing uncertainty about the efficacy of the operation was reflected in marked geographic variation in the rates of endarterectomy.
8
Adding to this uncertainty was the decline in . . .
A search for a massive resonance Formula: see textdecaying into a W and a Higgs boson in the Formula: see text (Formula: see text, Formula: see text) final state is presented. Results are based on ...data corresponding to an integrated luminosity of 19.7Formula: see text of proton-proton collisions at Formula: see text Formula: see text, collected using the CMS detector at the LHC. For a high-mass (Formula: see text1Formula: see text) resonance, the two bottom quarks coming from the Higgs boson decay are reconstructed as a single jet, which can be tagged by placing requirements on its substructure and flavour. Exclusion limits at 95 % confidence level are set on the production cross section of a narrow resonance decaying into WH, as a function of its mass. In the context of a little Higgs model, a lower limit on the Formula: see text mass of 1.4Formula: see text is set. In a heavy vector triplet model that mimics the properties of composite Higgs models, a lower limit on the Formula: see text mass of 1.5Formula: see text is set. In the context of this model, the results are combined with related searches to obtain a lower limit on the Formula: see text mass of 1.8Formula: see text, the most restrictive to date for decays to a pair of standard model bosons.
Full text
Available for:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Motivation
Discrimination statistics describe the ability of a survival model to assign higher risks to individuals who experience earlier events: examples are Harrell's C‐index and Royston and ...Sauerbrei's D, which we call the D‐index. Prognostic covariates whose distributions are controlled by the study design (e.g. age and sex) influence discrimination and can make it difficult to compare model discrimination between studies. Although covariate adjustment is a standard procedure for quantifying disease‐risk factor associations, there are no covariate adjustment methods for discrimination statistics in censored survival data.
Objective
To develop extensions of the C‐index and D‐index that describe the prognostic ability of a model adjusted for one or more covariate(s).
Method
We define a covariate‐adjusted C‐index and D‐index for censored survival data, propose several estimators, and investigate their performance in simulation studies and in data from a large individual participant data meta‐analysis, the Emerging Risk Factors Collaboration.
Results
The proposed methods perform well in simulations. In the Emerging Risk Factors Collaboration data, the age‐adjusted C‐index and D‐index were substantially smaller than unadjusted values. The study‐specific standard deviation of baseline age was strongly associated with the unadjusted C‐index and D‐index but not significantly associated with the age‐adjusted indices.
Conclusions
The proposed estimators improve meta‐analysis comparisons, are easy to implement and give a more meaningful clinical interpretation.
Full text
Available for:
BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
The pixel detector of the Compact Muon Solenoid experiment consists of three barrel layers and two disks for each endcap. The detector was installed in summer 2008, commissioned with charge ...injections, and operated in the 3.8 T magnetic field during cosmic ray data taking. This paper reports on the first running experience and presents results on the pixel tracker performance, which are found to be in line with the design specifications of this detector. The transverse impact parameter resolution measured in a sample of high momentum muons is 18 microns.
Signals consistent with the B_{c}^{+}(2S) and B_{c}^{*+}(2S) states are observed in proton-proton collisions at sqrts=13 TeV, in an event sample corresponding to an integrated luminosity of 143 ...fb^{-1}, collected by the CMS experiment during the 2015-2018 LHC running periods. These excited bover ¯c states are observed in the B_{c}^{+}π^{+}π^{-} invariant mass spectrum, with the ground state B_{c}^{+} reconstructed through its decay to J/ψπ^{+}. The two states are reconstructed as two well-resolved peaks, separated in mass by 29.1±1.5(stat)±0.7(syst) MeV. The observation of two peaks, rather than one, is established with a significance exceeding five standard deviations. The mass of the B_{c}^{+}(2S) meson is measured to be 6871.0±1.2(stat)±0.8(syst)±0.8(B_{c}^{+}) MeV, where the last term corresponds to the uncertainty in the world-average B_{c}^{+} mass.
Full text
Available for:
CMK, CTK, FMFMET, IJS, NUK, PNG, UL, UM
We present results from an analysis of B(0)B(0)--> rho(+)rho(-) using 232 x 10(6) Gamma (4S) --> BB decays collected with the BABAR detector at the PEP-II asymmetric-energy B factory at SLAC. We ...measure the longitudinal polarization fraction f(L) = 0.978 +/- 0.014(stat) + 0.021 / -0.029(syst) and the CP-violating parameters S(L)= -0.33 +/- 0.24(stat) + 0.08 / -0.14(syst) and C(L)= -0.03 +/- 0.18(stat) +/- 0.09(syst). Using an isospin analysis of B --> rhorho decays, we determine the unitarity triangle parameter alpha. The solution compatible with the standard model is alpha = (100 +/- 13) degrees.
Full text
Available for:
CMK, CTK, FMFMET, IJS, NUK, PNG, UM
The cross section for Formula: see text production in the all-jets final state is measured in pp collisions at a centre-of-mass energy of 8 Formula: see text at the LHC with the CMS detector, in data ...corresponding to an integrated luminosity of 18.4 Formula: see text. The inclusive cross section is found to be Formula: see text Formula: see text. The normalized differential cross sections are measured as a function of the top quark transverse momenta, Formula: see text, and compared to predictions from quantum chromodynamics. The results are reported at detector, parton, and particle levels. In all cases, the measured top quark Formula: see text spectra are significantly softer than theoretical predictions.
Full text
Available for:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Stringent limits are set on the long-lived lepton-like sector of the phenomenological minimal supersymmetric standard model (pMSSM) and the anomaly-mediated supersymmetry breaking (AMSB) model. The ...limits are derived from the results presented in a recent search for long-lived charged particles in proton-proton collisions, based on data collected by the CMS detector at a centre-of-mass energy of 8 TeV at the Large Hadron Collider. In the pMSSM parameter sub-space considered, 95.9 % of the points predicting charginos with a lifetime of at least 10 ns are excluded. These constraints on the pMSSM are the first obtained at the LHC. Charginos with a lifetime greater than 100 ns and masses up to about 800 GeV in the AMSB model are also excluded. The method described can also be used to set constraints on other models.
Full text
Available for:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
This paper presents distributions of topological observables in inclusive three- and four-jet events produced in pp collisions at a centre-of-mass energy of 7Formula: see text with a data sample ...collected by the CMS experiment corresponding to a luminosity of 5.1Formula: see text. The distributions are corrected for detector effects, and compared with several event generators based on two- and multi-parton matrix elements at leading order. Among the considered calculations, MadGraph interfaced with pythia6 displays the overall best agreement with data.
Full text
Available for:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Photolyses of Ru(salen)(NO)(OH
2)
+ and Ru(salen)(NO)Cl in aqueous solution at different pH’s result in the same photoproduct,
Ru
III
(
salen
)
(
OH
2
)
2
+
, with NO release. Photolysis of the ...chloro complex results also in chloride release via sequential photoreactions. The acidity of the coordinated water of Ru(salen)(NO)(OH
2)
+ (p
K
a
=
4.5) indicates that the ruthenium should have a Ru(III) character in this complex.
The photochemical behavior of nitrosyl complexes Ru(salen)(NO)(OH
2)
+ and Ru(salen)(NO)Cl (salen
=
N,N′-ethylenebis-(salicylideneiminato) dianion) in aqueous solution is described. Irradiation with light in the 350–450
nm range resulted in nitric oxide (NO) release from both. For Ru(salen)(NO)Cl secondary photoreactions also resulted in chloride aquation. Thus, in both cases the final photoproduct is the diaquo cation
Ru
III
(
salen
)
(
OH
2
)
2
+
, for which p
K
a’s of 5.9 and 9.1 were determined for the coordinated waters. The p
K
a of the Ru(salen)(NO)(OH
2)
+ cation was also determined as 4.5
±
0.1, and the relative acidities of these ruthenium aquo units are discussed in the context of the bonding interactions between Ru(III) and NO.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
You have reached the maximum number of search results that are displayed.
For better performance, the search offers a maximum of 1,000 results per query (or 50 pages if the option 10/page is selected).
Consider using result filters or changing the sort order to explore your results further.
PDF
