651 research outputs found

    Arterial stiffness and hand osteoarthritis: a novel relationship?

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    SummaryObjectiveOsteoarthritis (OA) and vascular stiffening may share elements of common pathogenesis, but their potential relatedness has been the focus of little prior inquiry. We tested the hypothesis that these two aging-associated conditions are related to each other.MethodWe analyzed cross-sectional data from 256 participants of the Baltimore Longitudinal Study of Aging (BLSA), a study of normative aging. All underwent measurement of arterial pulse wave velocity (PWV), an index of vascular stiffness, as well as hand radiographs that were graded for evidence of OA. Twenty total joints across three joint groups (distal interphalangeal [DIP], proximal interphalangeal [PIP], carpal-metacarpal [CMC]) were each assigned a Kellgren–Lawrence grade (K–L) of 0 (normal) through 4 (severe), with K–L grades ≥2 considered evidence of definite OA. Radiographic hand OA was defined as definite OA changes in at least two of the three anatomic hand sites (DIP, PIP, CMC). OA burden was represented by the total number of affected OA joints, and a cumulative K–L grade was aggregated across all hand joint groups. The relationship of PWV with these three measures of hand OA was assessed by linear regression.ResultsUpon univariate analysis, the presence of radiographic hand OA (β=218.1, P<0.01), the total number of OA joints (β=32.9, P<0.01), and the cumulative K–L grade across all joint groups (β=12.2, P<0.01) were each associated with increased PWV. These associations, however, were no longer significant in age-adjusted models.ConclusionAlthough significant individual relationships between PWV and several measures of hand OA were observed, these associations were largely attributable to the confounding effect of age

    Field quantization for open optical cavities

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    We study the quantum properties of the electromagnetic field in optical cavities coupled to an arbitrary number of escape channels. We consider both inhomogeneous dielectric resonators with a scalar dielectric constant ϵ(r)\epsilon({\bf r}) and cavities defined by mirrors of arbitrary shape. Using the Feshbach projector technique we quantize the field in terms of a set of resonator and bath modes. We rigorously show that the field Hamiltonian reduces to the system--and--bath Hamiltonian of quantum optics. The field dynamics is investigated using the input--output theory of Gardiner and Collet. In the case of strong coupling to the external radiation field we find spectrally overlapping resonator modes. The mode dynamics is coupled due to the damping and noise inflicted by the external field. For wave chaotic resonators the mode dynamics is determined by a non--Hermitean random matrix. Upon including an amplifying medium, our dynamics of open-resonator modes may serve as a starting point for a quantum theory of random lasing.Comment: 16 pages, added references, corrected typo

    Inhomogeneous magnetism in La-doped CaMnO3. (I) Nanometric-scale spin clusters and long-range spin canting

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    Neutron measurements on Ca{1-x}La{x}MnO3 (0.00 <= x <= 0.20) reveal the development of a liquid-like spatial distribution of magnetic droplets of average size ~10 Angstroms, the concentration of which is proportional to x (one cluster per ~60 doped electrons). In addition, a long-range ordered ferromagnetic component is observed for ~0.05 < x < ~0.14. This component is perpendicularly coupled to the simple G-type antiferromagnetic (G-AFM) structure of the undoped compound, which is a signature of a G-AFM + FM spin-canted state. The possible relationship between cluster formation and the stabilization of a long-range spin-canting for intermediate doping is discussed.Comment: Submitted to Physical Review

    Alpha-1 antitrypsin mitigates the inhibition of airway epithelial cell repair by neutrophil elastase

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    Copyright © 2016 by the American Thoracic Society. Neutrophil elastase (NE) activity is associated with many destructive lung diseases and is a predictor for structural lung damage in early cystic fibrosis (CF), which suggests normal maintenance of airway epitheliumis prevented byuninhibitedNE.However, limited data exist on how the NE activity in airways of very young children with CF affects function of the epithelia. The aimof this studywas to determine if NE activity could inhibit epithelial homeostasis and repair and whether any functional effect was reversible by antiprotease alpha-1 antitrypsin (a1AT) treatment. Viability, inflammation, apoptosis, and proliferation were assessed in healthy non-CF and CF pediatric primary airway epithelial cells (pAEC non-CF and pAEC CF , respectively) during exposure to physiologically relevant NE. The effect of NE activity on pAEC CF wound repair was also assessed.We report that viability after 48 hours was significantly decreased by 100 nM NE in pAEC non-CF and pAEC CF owing to rapid cellular detachment that was accompanied by inflammatory cytokine release. Furthermore, both phenotypes initiated an apoptotic response to 100 nM NE, whereas ≥50 nM NE activity significantly inhibited the proliferative capacity of cultures. Similar concentrations of NE also significantly inhibited wound repair of pAEC CF , but this effect was reversed by the addition of a1AT. Collectively, our results demonstrate free NE activity is deleterious for epithelial homeostasis and support the hypothesis that proteases inthe airway contribute directly toCF structural lung disease. Our results also highlight the need to investigate antiprotease therapies in early CF disease in more detail

    Analysis of Two-Body Decays of Charmed Baryons Using the Quark-Diagram Scheme

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    We give a general formulation of the quark-diagram scheme for the nonleptonic weak decays of baryons. We apply it to all the decays of the antitriplet and sextet charmed baryons and express their decay amplitudes in terms of the quark-diagram amplitudes. We have also given parametrizations for the effects of final-state interactions. For SU(3) violation effects, we only parametrize those in the horizontal WW-loop quark diagrams whose contributions are solely due to SU(3)-violation effects. In the absence of all these effects, there are many relations among various decay modes. Some of the relations are valid even in the presence of final-state interactions when each decay amplitude in the relation contains only a single phase shift. All these relations provide useful frameworks to compare with future experiments and to find out the effects of final-state interactions and SU(3) symmetry violations.Comment: 28 pages, 20 Tables in landscape form, 4 figures. Main changes are: (i) some errors in the Tables and in the relations between the quark-diagram amplitudes of this paper and those of Ref.[10] are corrected, (ii) improvements are made in the presentation so that comparisons with previous works and what have been done to include SU(3) breaking and final-state interactions are more clearly stated; to appear in the Physical Review

    Possible implications of the channeling effect in NaI(Tl) crystals

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    The channeling effect of low energy ions along the crystallographic axes and planes of NaI(Tl) crystals is discussed in the framework of corollary investigations on WIMP Dark Matter candidates. In fact, the modeling of this existing effect implies a more complex evaluation of the luminosity yield for low energy recoiling Na and I ions. In the present paper related phenomenological arguments are developed and possible implications are discussed at some extent.Comment: 16 pages, 10 figures, preprint ROM2F/2007/15, submitted for publicatio

    Synthesis and Antibacterial Evaluation of Cephalosporin Isosteres

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    As part of a program to explore the chemistry of β-lactams and their derivatives, we prepared a focused set of benzazetidine, indoline, and indole heterocycles, as well as flexible unconstrained variations of the four-membered heterocyclic compounds. These analogues mimic the three-dimensional shape of cephalosporins but are not prone to covalent binding via ring opening. Although these analogues were inactive against the ESKAPE pathogens and Mtb, they represent unique and underexplored chemotypes for future biological screening

    Observation of hard scattering in photoproduction events with a large rapidity gap at HERA

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    Events with a large rapidity gap and total transverse energy greater than 5 GeV have been observed in quasi-real photoproduction at HERA with the ZEUS detector. The distribution of these events as a function of the Îłp\gamma p centre of mass energy is consistent with diffractive scattering. For total transverse energies above 12 GeV, the hadronic final states show predominantly a two-jet structure with each jet having a transverse energy greater than 4 GeV. For the two-jet events, little energy flow is found outside the jets. This observation is consistent with the hard scattering of a quasi-real photon with a colourless object in the proton.Comment: 19 pages, latex, 4 figures appended as uuencoded fil

    Deriving the dietary approaches to stop hypertension (DASH) score in women from seven pregnancy cohorts from the European alphabet consortium

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    The ALPHABET consortium aims to examine the interplays between maternal diet quality, epigenetics and offspring health in seven pregnancy/birth cohorts from five European countries. We aimed to use the Dietary Approaches to Stop Hypertension (DASH) score to assess diet quality, but different versions have been published. To derive a single DASH score allowing cross-country, cross-cohort and cross-period comparison and limiting data heterogeneity within the ALPHABET consortium, we harmonised food frequency questionnaire (FFQ) data collected before and during pregnancy in ≥26,500 women. Although FFQs differed strongly in length and content, we derived a consortium DASH score composed of eight food components by combining the prescriptive original DASH and the DASH described by Fung et al. Statistical issues tied to the nature of the FFQs led us to re-classify two food groups (grains and dairy products). Most DASH food components exhibited pronounced between-cohort variability, including non-full-fat dairy products (median intake ranging from 0.1 to 2.2 servings/day), sugar-sweetened beverages/sweets/added sugars (0.3–1.7 servings/day), fruits (1.1–3.1 servings/day), and vegetables (1.5–3.6 servings/day). We successfully developed a harmonized DASH score adapted to all cohorts being part of the ALPHABET consortium. This methodological work may benefit other research teams in adapting the DASH to their study’s specificities
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