10,757 research outputs found

    Within-Home versus Between-Home Variability of House Dust Endotoxin in a Birth Cohort

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    Endotoxin exposure has been proposed as an environmental determinant of allergen responses in children. To better understand the implications of using a single measurement of house dust endotoxin to characterize exposure in the first year of life, we evaluated room-specific within-home and between-home variability in dust endotoxin obtained from 470 households in Boston, Massachusetts. Homes were sampled up to two times over 5–11 months. We analyzed 1,287 dust samples from the kitchen, family room, and baby’s bedroom for endotoxin. We fit a mixed-effects model to estimate mean levels and the variation of endotoxin between homes, between rooms, and between sampling times. Endotoxin ranged from 2 to 1,945 units per milligram of dust. Levels were highest during summer and lowest in the winter. Mean endotoxin levels varied significantly from room to room. Cross-sectionally, endotoxin was moderately correlated between family room and bedroom floor (r = 0.30), between family room and kitchen (r = 0.32), and between kitchen and bedroom (r = 0.42). Adjusting for season, the correlation of endotoxin levels within homes over time was 0.65 for both the bedroom and kitchen and 0.54 for the family room. The temporal within-home variance of endotoxin was lowest for bedroom floor samples and highest for kitchen samples. Between-home variance was lowest in the family room and highest for kitchen samples. Adjusting for season, within-home variation was less than between-home variation for all three rooms. These results suggest that room-to-room and home-to-home differences in endotoxin influence the total variability more than factors affecting endotoxin levels within a room over time

    Vitamin or antioxidant intake (or serum level) and risk of cervical neoplasm: a meta‐analysis

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    Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/86903/1/BJO_3032_sm_TableS1.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/86903/2/j.1471-0528.2011.03032.x.pd

    A chiral HPLC-MS/MS method for simultaneous quantification of warfarin enantiomers and its major hydroxylation metabolites of CYP2C9 and CYP3A4 in human plasma

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    Warfarin is an oral anticoagulant that requires frequent therapeutic drug monitoring due to a narrow therapeutic window, considerable interindividual variability in drug response, and susceptibility to drug-drug and drug-diet interactions. Enantiomeric separation and quantification of warfarin enantiomers and clinically important major hydroxylation metabolites are essential for drug interaction studies and phenotypic characterization of CYP2C9 and CYP3A4, the major Cytochrome P450 (CYP) enzymes involved in warfarin metabolism. Here, we describe the development and validation of a chiral high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS)-based quantification of R-warfarin, S-warfarin, S-7-hydroxywarfarin (the major CYP2C9metabolite) and (9R; 10S)-10-hydroxywarfarin (the CYP3A4 metabolite) in human plasma. Simple protein precipitation-based extraction showed good recovery of analytes (82.9 - 96.9%). The developed method exhibited satisfactory intra-day and inter-day accuracy and precision. The lower limits of detection were 0.25nM (or ~0.08 ng/ml) for the warfarin enantiomers and 0.1nM (or ~0.04 ng/mL) for S-7-hydroxywarfarinand (9R; 10S)-10-hydroxywarfarin using only 50μL plasma during extraction. The validated method was successfully applied to analyze plasma samples obtained from a healthy human subject who enrolled in a clinical drug interaction study involving warfarin

    EM Decay of X(3872) as the 11D2(2+)1{^1D_2}(2^{-+}) charmonium

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    The recently BaBar results raise the possibility that X(3872) has negative parity. This makes people reconsider assigning X(3872) to the 11D2(ccˉ)1{^1D_2}(c\bar c) state. In this paper we give a general form of the wave function of 2+2^{-+} mesons. By solving the instantaneous Bethe-Salpeter equation, we get the mass spectrum and corresponding wave functions. We calculate electromagnetic decay widths of the first 2+2^{-+} state which we assume to be the X(3872) particle. The results are Γ(2+(3872)J/ψγ)=1.590.42+0.53\Gamma(2^{-+}(3872)\rightarrow J/\psi\gamma) = 1.59^{+0.53}_{-0.42} keV, Γ(2+(3872)ψ(2S)γ)=2.870.97+1.46\Gamma(2^{-+}(3872)\rightarrow \psi(2S)\gamma) = 2.87^{+1.46}_{-0.97} eV and Γ(2+(3872)ψ(3770)γ)=0.1350.047+0.066\Gamma(2^{-+}(3872)\rightarrow \psi(3770)\gamma) = 0.135^{+0.066}_{-0.047} keV. The ratio of branch fractions of the second and first channel is about 0.002, which is inconsistent with the experimental value 3.4±1.43.4\pm 1.4. So X(3872) is unlikely to be a 2+2^{-+} charmonium state. In addition, we obtain a relatively large decay width for 2+(3872)hcγ2^{-+}(3872)\rightarrow h_c\gamma channel which is 392111+62392^{+62}_{-111} keV.Comment: Revised versio

    Hybrid Design for Advanced Magnetic Recording Media : Combining Exchange-Coupled Composite Media with Coupled Granular Continuous Media

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    In order to enhance the performance of advanced granular recording media and understand the physics behind the mechanism of the reversal process, an atomistic spin-dynamics simulation is used to investigate theoretically the magnetic properties and the magnetization-reversal behavior for a composite media design. This model allows us to investigate the effect of the magnetostatic interaction and inter- and intralayer exchange coupling for a realistic system. The composite granular medium investigated consists of hard and soft composite layers in which the grains are well segregated with a continuous capping layer deposited to provide uniform exchange coupling. We present a detailed calculation aimed to reveal the reversal mechanism. In particular, the angular dependence of the critical field is investigated to understand the switching process. The calculations show a complex reversal mechanism driven by the magnetostatic interaction. It is also demonstrated, at high sweep rates consistent with the recording process, that thermal effects lead to a significant and irreducible contribution to the switching field distribution

    Criminal Justice and Suicide Outcomes with Indiana's Risk-Based Gun Seizure Law

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    This article examines the application and effectiveness of a 2006 Indiana law designed to prevent gun violence by authorizing police officers to separate firearms from persons who present imminent or future risk of injury to self or others, or display a propensity for violent or emotionally unstable conduct. A court hearing is held to determine ongoing risk in these cases; a judge decides whether to return the seized firearms or retain them for up to five years. The study examines the frequency of criminal arrest as well as suicide outcomes for 395 gun-removal actions in Indiana. Fourteen individuals (3.5%) died from suicide, seven (1.8%) using a firearm. The study population's annualized suicide rate was about 31 times higher than that of the general adult population in Indiana, demonstrating that the law is being applied to a population genuinely at high risk. By extrapolating information on the case fatality rate for different methods of suicide, we calculated that one life was saved for every 10 gun-removal actions, similar to results of a previous study in Connecticut. Perspectives from key stakeholders are also presented along with implications for gun policy reform and implementation

    Revisiting vertical structure of neutrino-dominated accretion disks: Bernoulli parameter, neutrino trapping and other distributions

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    We revisit the vertical structure of neutrino dominated accretion flows (NDAFs) in spherical coordinates with a new boundary condition based on the mechanical equilibrium. The solutions show that NDAF is significantly thick. The Bernoulli parameter and neutrino trapping are determined by the mass accretion rate and the viscosity parameter. According to the distribution of the Bernoulli parameter, the possible outflow may appear in the outer region of the disk. The neutrino trapping can essentially affect the neutrino radiation luminosity. The vertical structure of NDAF is like a "sandwich", and the multilayer accretion may account for the flares in gamma-ray bursts.Comment: 7 pages, 2 figures, Accepted for publication in Astrophysics & Space Scienc
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