528 research outputs found

    On Relativistic Quantum Information Properties of Entangled Wave Vectors of Massive Fermions

    Full text link
    We study special relativistic effects on the entanglement between either spins or momenta of composite quantum systems of two spin-1/2 massive particles, either indistinguishable or distinguishable, in inertial reference frames in relative motion. For the case of indistinguishable particles, we consider a balanced scenario where the momenta of the pair are well-defined but not maximally entangled in the rest frame while the spins of the pair are described by a one-parameter (Ρ\eta) family of entangled bipartite states. For the case of distinguishable particles, we consider an unbalanced scenario where the momenta of the pair are well-defined and maximally entangled in the rest frame while the spins of the pair are described by a one-parameter (Ξ\xi) family of non-maximally entangled bipartite states. In both cases, we show that neither the spin-spin (ssss) nor the momentum-momentum (mmmm) entanglements quantified by means of Wootters' concurrence are Lorentz invariant quantities: the total amount of entanglement regarded as the sum of these entanglements is not the same in different inertial moving frames. In particular, for any value of the entangling parameters, both ssss and mmmm-entanglements are attenuated by Lorentz transformations and their parametric rates of change with respect to the entanglements observed in a rest frame have the same monotonic behavior. However, for indistinguishable (distinguishable) particles, the change in entanglement for the momenta is (is not) the same as the change in entanglement for spins. As a consequence, in both cases, no entanglement compensation between spin and momentum degrees of freedom occurs.Comment: 21 pages, 8 figure

    Association of measures of body fat with serum alpha-tocopherol and its metabolites in middle-aged individuals

    Get PDF
    Background and aims: The accumulation of fat increases the formation of lipid perox-ides, which are partly scavenged by alpha-tocopherol (a-TOH). Here, we aimed to investigate the associations between different measures of (abdominal) fat and levels of urinary a-TOH metab-olites in middle-aged individuals. Methods and results: In this cross-sectional analysis in the Netherlands Epidemiology of Obesity study (N Z 511, 53% women; mean [SD] age of 55 [6.1] years), serum a-TOH and a-TOH metab-olites from 24-h urine were measured as alpha-tocopheronolactone hydroquinone (a-TLHQ, oxidized) and alpha-carboxymethyl-hydroxychroman (a-CEHC, enzymatically converted) using liquid-chromatography-tandem mass spectrometry. Body mass index and total body fat were measured, and abdominal subcutaneous and visceral adipose tissue (aSAT and VAT) were as-sessed using magnetic resonance imaging. Using multivariable-adjusted linear regression ana -lyses, we analysed the associations of BMI, TBF, aSAT and VAT with levels of urinary a-TOH metabolites, adjusted for confounders. We observed no evidence for associations between body fat measures and serum a-TOH. Higher BMI and TBF were associated with lower urinary levels of TLHQ (0.95 [95%CI: 0.90, 1.00] and 0.94 [0.88, 1.01] times per SD, respectively) and with lower TLHQ relative to CEHC (0.93 [0.90, 0.98] and 0.93 [0.87, 0.98] times per SD, respectively). We observed similar associations for VAT (TLHQ: 0.94 [0.89, 0.99] times per SD), but not for aSAT. Conclusions: Opposite to our research hypothesis, higher abdominal adiposity was moderately associated with lower levels of oxidized a-TOH metabolites, which might reflect lower vitamin E antioxidative activity in individuals with higher abdominal fat instead. (c) 2021 The Author(s). Published by Elsevier B.V. on behalf of The Italian Diabetes Society, the Italian Society for the Study of Atherosclerosis, the Italian Society of Human Nutrition and the Department of Clinical Medicine and Surgery, Federico II University. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).Diabetes mellitus: pathophysiological changes and therap

    Associations between lifestyle factors and vitamin E metabolites in the general population

    Get PDF
    The antioxidant vitamin E (alpha-tocopherol, alpha-TOH) protects lipids from oxidation by reactive oxygen species. We hypothesized that lifestyle factors associate with vitamin E metabolism marked by urinary alpha-tocopheronolactone hydroquinone (alpha-TLHQ) and alpha-carboxymethyl-hydroxychroman (alpha-CEHC levels), as potential reflection of lipid oxidation. We conducted a cross-sectional study in the Netherlands Epidemiology of Obesity Study. Serum alpha-TOH, and urinary alpha-TLHQ and alpha-CEHC were quantified by liquid chromatography coupled with tandem mass spectrometry. Information on the lifestyle factors (sleep, physical activity (PA), smoking and alcohol) were collected through questionnaires. Multivariable linear regression analyses were performed to assess the associations between the lifestyle factors and alpha-TOH measures. A total of 530 participants (46% men) were included with mean (SD) age of 56 (6) years. Of the examined lifestyle factors, only poor sleep was associated with a higher serum alpha-TOH (mean difference: 4% (95% CI: 1, 7%)). Current smoking was associated with higher urinary alpha-CEHC (32%: (14%, 53%)), with evidence of a dose-response relationship with smoking intensity (low pack years, 24% (2, 52%); high pack years, 55% (25, 93%)). Moderate physical activity was associated with a lower alpha-TLHQ relative to alpha-CEHC (-17%: (-26, -6%), compared with low PA). Only specific lifestyle factors associate with vitamin E metabolism. Examining serum alpha-TOH does not provide complete insight in vitamin E antioxidant capacity.Public Health and primary carePrevention, Population and Disease management (PrePoD

    Associations of metabolomic profiles with circulating vitamin E and urinary vitamin E metabolites in middle-aged individuals

    Get PDF
    Vitamin E (alpha-tocopherol [alpha-TOH] ) is transported in lipoprotein particles in blood, but little is known about the transportation of its oxidized metabolites. In the Netherlands Epidemiology of Obesity Study, we aimed to investigate the associations of 147 circulating metabolomic measures obtained through targeted nuclear magnetic resonance with serum alpha-TOH and its urinary enzymatic (alpha-CEHC) and oxidized (alpha-TLHQ) metabolites from 24-h urine quantified by liquid chromatography with tandem mass spectrometry. Multivariable linear regression analyses, in which multiple testing was taken into account, were performed to assess associations between metabolomic measures (determinants; standardized to mean = 0, SD = 1) and vitamin E metabolites (outcomes), adjusted for demographic factors. We analyzed 474 individuals (55% women, 45% men) with a mean (SD) age of 55.7 (6.0) y. Out of 147 metabolomic measures, 106 were associated (P < 1.34 x 10(3)) with serum alpha-TOH (median beta [interquartile range] = 0.416 [0.383-0.466]), predominantly lipoproteins associated with higher alpha-TOH. The associations of metabolomic measures with urinary alpha-CEHC have directions similar to those with alpha-TOH, but effect sizes were smaller and non-significant (median beta [interquartile range] = 0.065 [0.047-0.084]). However, associations of metabolomic measures with urinary alpha-TLHQ were markedly different from those with both serum alpha-TOH and urinary alpha-CEHC, with negative and small-to-null relations to most very-low-density lipoproteins and amino acids. Therefore, our results highlight the differences in the lipoproteins involved in the transportation of circulating alpha-TOH and oxidized vitamin E metabolites. This indicates that circulating alpha-TOH may be representative of the enzymatic but not the antioxidative function of vitamin E. (C) 2021 The Author( s). Published by Elsevier Inc.Clinical epidemiolog

    Urinary oxidized, but not enzymatic vitamin E metabolites are inversely associated with measures of glucose homeostasis in middle-aged healthy individuals

    Get PDF
    Summary Background & aims Damage induced by lipid peroxidation has been associated with impaired glucose homeostasis. Vitamin E (α-tocopherol, α-TOH) competitively reacts with lipid peroxyl radicals to mitigate oxidative damage, and forms oxidized vitamin E metabolites. Accordingly, we aimed to investigate the associations between α-TOH metabolites (oxidized and enzymatic) in both circulation and urine and measures of glucose homeostasis in the general middle-aged population. Methods This cross-sectional study was embedded in the population-based Netherlands Epidemiology of Obesity (NEO) Study. α-TOH metabolites in blood (α-TOH and α-CEHC-SO3) and urine [sulfate (SO3) and glucuronide (GLU) of both α-TLHQ (oxidized) and α-CEHC (enzymatic)] were quantified by liquid chromatography coupled with tandem mass spectrometry (LC/MS–MS). Measures of glucose homeostasis (HOMA-B, HOMA-IR, Insulinogenic index and Matsuda index) were obtained from fasting and postprandial blood samples. Multivariable linear regression analyses were performed to assess the associations of α-TOH metabolites and measures of glucose homeostasis. Results We included 498 participants (45% men) with mean (SD) age of 55.8 (6.1) years who did not use glucose-lowering medication. While blood α-TOH was not associated with measures of glucose homeostasis, urinary oxidized metabolites (α-TLHQ-SO3/GLU) were associated with HOMA-IR and Matsuda index. For example, a one-SD higher α-TLHQ-SO3 was associated with 0.92 (95% CI: 0.87, 0.97) fold lower HOMA-IR and 1.06 (1.01, 1.11) fold higher Matsuda index, respectively. Similar results were obtained for the urinary α-TLHQ to α-CEHC ratio as a measure of oxidized-over-enzymatic conversion of α-TOH. Conclusion Higher urinary levels of oxidized α-TOH metabolites as well as higher oxidized-to-enzymatic α-TOH metabolite ratio, but not circulating α-TOH or enzymatic metabolites, were associated with lower insulin resistance. Rather than circulating α-TOH, estimates of the conversion of α-TOH might be informative in relation to health and disease.Clinical epidemiolog

    Search for a W' boson decaying to a bottom quark and a top quark in pp collisions at sqrt(s) = 7 TeV

    Get PDF
    Results are presented from a search for a W' boson using a dataset corresponding to 5.0 inverse femtobarns of integrated luminosity collected during 2011 by the CMS experiment at the LHC in pp collisions at sqrt(s)=7 TeV. The W' boson is modeled as a heavy W boson, but different scenarios for the couplings to fermions are considered, involving both left-handed and right-handed chiral projections of the fermions, as well as an arbitrary mixture of the two. The search is performed in the decay channel W' to t b, leading to a final state signature with a single lepton (e, mu), missing transverse energy, and jets, at least one of which is tagged as a b-jet. A W' boson that couples to fermions with the same coupling constant as the W, but to the right-handed rather than left-handed chiral projections, is excluded for masses below 1.85 TeV at the 95% confidence level. For the first time using LHC data, constraints on the W' gauge coupling for a set of left- and right-handed coupling combinations have been placed. These results represent a significant improvement over previously published limits.Comment: Submitted to Physics Letters B. Replaced with version publishe

    Search for the standard model Higgs boson decaying into two photons in pp collisions at sqrt(s)=7 TeV

    Get PDF
    A search for a Higgs boson decaying into two photons is described. The analysis is performed using a dataset recorded by the CMS experiment at the LHC from pp collisions at a centre-of-mass energy of 7 TeV, which corresponds to an integrated luminosity of 4.8 inverse femtobarns. Limits are set on the cross section of the standard model Higgs boson decaying to two photons. The expected exclusion limit at 95% confidence level is between 1.4 and 2.4 times the standard model cross section in the mass range between 110 and 150 GeV. The analysis of the data excludes, at 95% confidence level, the standard model Higgs boson decaying into two photons in the mass range 128 to 132 GeV. The largest excess of events above the expected standard model background is observed for a Higgs boson mass hypothesis of 124 GeV with a local significance of 3.1 sigma. The global significance of observing an excess with a local significance greater than 3.1 sigma anywhere in the search range 110-150 GeV is estimated to be 1.8 sigma. More data are required to ascertain the origin of this excess.Comment: Submitted to Physics Letters

    Measurement of the Lambda(b) cross section and the anti-Lambda(b) to Lambda(b) ratio with Lambda(b) to J/Psi Lambda decays in pp collisions at sqrt(s) = 7 TeV

    Get PDF
    The Lambda(b) differential production cross section and the cross section ratio anti-Lambda(b)/Lambda(b) are measured as functions of transverse momentum pt(Lambda(b)) and rapidity abs(y(Lambda(b))) in pp collisions at sqrt(s) = 7 TeV using data collected by the CMS experiment at the LHC. The measurements are based on Lambda(b) decays reconstructed in the exclusive final state J/Psi Lambda, with the subsequent decays J/Psi to an opposite-sign muon pair and Lambda to proton pion, using a data sample corresponding to an integrated luminosity of 1.9 inverse femtobarns. The product of the cross section times the branching ratio for Lambda(b) to J/Psi Lambda versus pt(Lambda(b)) falls faster than that of b mesons. The measured value of the cross section times the branching ratio for pt(Lambda(b)) > 10 GeV and abs(y(Lambda(b))) < 2.0 is 1.06 +/- 0.06 +/- 0.12 nb, and the integrated cross section ratio for anti-Lambda(b)/Lambda(b) is 1.02 +/- 0.07 +/- 0.09, where the uncertainties are statistical and systematic, respectively.Comment: Submitted to Physics Letters

    Search for new physics in events with opposite-sign leptons, jets, and missing transverse energy in pp collisions at sqrt(s) = 7 TeV

    Get PDF
    A search is presented for physics beyond the standard model (BSM) in final states with a pair of opposite-sign isolated leptons accompanied by jets and missing transverse energy. The search uses LHC data recorded at a center-of-mass energy sqrt(s) = 7 TeV with the CMS detector, corresponding to an integrated luminosity of approximately 5 inverse femtobarns. Two complementary search strategies are employed. The first probes models with a specific dilepton production mechanism that leads to a characteristic kinematic edge in the dilepton mass distribution. The second strategy probes models of dilepton production with heavy, colored objects that decay to final states including invisible particles, leading to very large hadronic activity and missing transverse energy. No evidence for an event yield in excess of the standard model expectations is found. Upper limits on the BSM contributions to the signal regions are deduced from the results, which are used to exclude a region of the parameter space of the constrained minimal supersymmetric extension of the standard model. Additional information related to detector efficiencies and response is provided to allow testing specific models of BSM physics not considered in this paper.Comment: Replaced with published version. Added journal reference and DO
    • …
    corecore