9,534 research outputs found

    Cosmology-independent Estimate of the Fraction of Baryon Mass in the IGM from Fast Radio Burst Observations

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    The excessive dispersion measure (DM) of fast radio bursts (FRBs) has been proposed to be a powerful tool to study intergalactic medium (IGM) and to perform cosmography. One issue is that the fraction of baryons in the IGM, f IGM, is not properly constrained. Here, we propose a method of estimating f IGM using a putative sample of FRBs with the measurements of both DM and luminosity distance d L. The latter can be obtained if the FRB is associated with a distance indicator (e.g., a gamma-ray burst or a gravitational-wave event), or the redshift z of the FRB is measured and d L at the corresponding z is available from other distance indicators (e.g., SNe Ia) at the same redshift. As d L/DM essentially does not depend on cosmological parameters, our method can determine f IGM independent of cosmological parameters. We parameterize f IGM as a function of redshift and model the DM contribution from a host galaxy as a function of star formation rate. Assuming f IGM has a mild evolution with redshift with a functional form and by means of Monte Carlo simulations, we show that an unbiased and cosmology-independent estimate of the present value of f IGM with a ~12% uncertainty can be obtained with 50 joint measurements of d L and DM. In addition, such a method can also lead to a measurement of the mean value of DM contributed from the local host galaxy

    Assessment of Carotid Arterial Wall Elasticity in Type 2 Diabetes Mellitus Patients with Microalbuminuria by Real-Time Ultrasound Elastography

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    The aim of this study was to evaluate carotid arterial wall elasticity in type 2 diabetes mellitus (T2DM) with microalbuminuria by real-time ultrasound elastography. Two hundred and ten T2DM patients were divided into two groups according to levels of urinary albumin excretion (UAE): T2DM without microalbuminuria (T2DM1 group, 120) and T2DM with microalbuminuria (T2DM2 group, 90). The right common carotid arteries were examined by real-time ultrasound elastography. The strain ratio (SR, blood to arterial wall strain ratio) was calculated by dividing the strain value of the blood by that of the carotid arterial wall. The correlation between SR and general data was analyzed. The mean SR value ± SD of T2DM2 group was significantly higher than that of T2DM1 group (P < 0.05). SR was positively and significantly correlated with UAE, HbA1c, and systolic blood pressure (r = 0.456,0.435,0.235, P < 0.05 for all). The mean value ± SD of UAE, HbA1c, 2hPG, BMI, and TC of T2DM2 group was significantly higher than that of T2DM1 group (P < 0.05 for all). In conclusion, there is an association between microalbuminuria and carotid arterial wall elasticity in T2DM patients

    3-(2-Amino­ethyl)-2-anilinoquinazolin-4(3H)-one methanol hemisolvate

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    The title methanol hemisolvated quinazolin-(3H)-one, C16H16N4O·0.5CH3OH, has an anilino substituent in the 2-position and an amino­ethyl substituent in the 3-position of the planar fused-ring system (r.m.s. deviation = 0.019 Å). The anilino N atom donates an intramolecular hydrogen bond to the amino­ethyl N atom. The mol­ecule and the solvent methanol mol­ecule are linked by N—H⋯N, N—H⋯O and O—H⋯O hydrogen bonds. The methanol mol­ecule is disordered over two equally occupied positions about a twofold rotation axis

    Analysis on the vehicle-bridge coupled vibrations of long-span cable-stayed bridge based on multiscale model

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    The paper introduces the principals and methods of universal multiscale modeling, and simply verifies them. It also derives the vibration equations of the bridge and the vehicles, and programs the universal program for analyzing two-axle vehicle-bridge coupled vibration via Ansys and Matlab software based on Newmark-β method. It proposes the universal method for analyzing vehicle-bridge coupled vibrations of long-span cable-stayed bridge based on multiscale model, and takes a single pylon cable-stayed bridge as an example to analyze and verify it

    Taxonomy and phylogeny of Sidera (Hymenochaetales, Rickenella clade) from China and North America revealing two new species

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    Sidera, belonging to the Rickenella clade of Hymenochaetales, is a worldwide genus with mostly poroid hymenophore of wood-inhabiting fungi. Two new species in the genus, Sidera americana and S. borealis, are described and illustrated from China and North America based on morphological and molecular evidence. They were mainly found growing on rotten wood of Abies, Picea and Pinus. S. americana is characterized by annual, resupinate basidiomata with silk sheen when dry, round pores (9–11 per mm), a dimitic hyphal system, and allantoid basidiospores measuring 3.5–4.2 × 1 μm. S. borealis is characterized by annual, resupinate basidiomata with cream to pinkish buff dry pore surface, angular pores (6–7 per mm), a dimitic hyphal system, and allantoid basidiospores measuring 3.9–4.1 × 1–1.1 μm. Phylogenetic analysis based on a combined 2-locus dataset [ITS1-5.8S-ITS2 (ITS) + nuclear large subunit RNA (nLSU)] shows that the two species are members of Sidera, and they are compared with morphologically similar and phylogenetically related species, respectively. An identification key to 18 accepted species of Sidera in worldwide is provided
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