158 research outputs found

    Characterization of Polyphosphoesters by Fourier Transform Ion Cyclotron Resonance Mass Spectrometry

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    FT-ICR mass spectrometry, together with collision-induced dissociation and electron capture dissociation, has been used to characterize the polyphosphoester poly[1,4-bis(hydroxyethyl)terephthalate-alt-ethyloxyphosphate] and its degradation products. Three degradation pathways were elucidated: hydrolysis of the phosphate–[1,4-bis(hydroxyethyl)terephthalate]bonds; hydrolysis of the phosphate–ethoxy bonds; and hydrolysis of the ethyl–terephthalate bonds. The dominant degradation reactions were those that involved the phosphate groups. This work constitutes the first application of mass spectrometry to the characterization of polyphosphoesters and demonstrates the suitability of high mass accuracy FT-ICR mass spectrometry, with CID and ECD, for the structural analysis of polyphosphoesters and their degradation products

    Phase Separation of Rigid-Rod Suspensions in Shear Flow

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    We analyze the behavior of a suspension of rigid rod-like particles in shear flow using a modified version of the Doi model, and construct diagrams for phase coexistence under conditions of constant imposed stress and constant imposed strain rate, among paranematic, flow-aligning nematic, and log-rolling nematic states. We calculate the effective constitutive relations that would be measured through the regime of phase separation into shear bands. We calculate phase coexistence by examining the stability of interfacial steady states and find a wide range of possible ``phase'' behaviors.Comment: 23 pages 19 figures, revised version to be published in Physical Review

    Solitary neurofibroma of the gingiva with prominent differentiation of Meissner bodies : a case report

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    <p>Abstract</p> <p>Background</p> <p>Oral neurofibromas are peripheral nerve sheath tumors, similar to schwannomas. Histological variations in oral neurofibromas are relatively uncommon.</p> <p>Case presentation</p> <p>Here, we present a case of unique variation in the observed characteristics of a neurofibroma, with no relation to neurofibromatosis type-1 or von Recklinghausen disease of the skin. The neurofibroma was observed in the right mandibular gingiva of a 32-year-old Japanese woman. Histologically, it differed from conventional neurofibromas in that the tumor was composed of a mixture of fine fibrillary collagen in sheets and/or cords of neoplastic Schwann cells containing numerous clusters of Meissner bodies. Histologically, these bodies were in contact with neoplastic Schwann cells. The Meissner bodies were immunopositive for S-100 protein, neuron-specific enolase, and vimentin, but were negative for calretinin. CD34-positive spindle cells were observed around the Meissner bodies. No recurrence or signs of other tumors have been observed in the patient for 5 years after tumor resection.</p> <p>Conclusion</p> <p>To the best of our knowledge, no formal descriptions of sporadic, solitary neurofibromas containing numerous Meissner bodies occurring in the oral cavity are available in literature. We believe that an uncommon proliferation of Meissner bodies, as seen in the present case, may result from aberrant differentiation of neoplastic Schwann cells.</p

    Measurements of B-mode Polarization of the Cosmic Microwave Background from 500 Square Degrees of SPTpol Data

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    We report a B-mode power spectrum measurement from the cosmic microwave background (CMB) polarization anisotropy observations made using the SPTpol instrument on the South Pole Telescope. This work uses 500 deg2^2 of SPTpol data, a five-fold increase over the last SPTpol B-mode release. As a result, the bandpower uncertainties have been reduced by more than a factor of two, and the measurement extends to lower multipoles: 52<<230152 < \ell < 2301. Data from both 95 and 150 GHz are used, allowing for three cross-spectra: 95 GHz x 95 GHz, 95 GHz x 150 GHz, and 150 GHz x 150 GHz. B-mode power is detected at very high significance; we find P(BB<0)=5.8×1071P(BB < 0) = 5.8 \times 10^{-71}, corresponding to a 18.1σ18.1 \sigma detection of power. An upper limit is set on the tensor-to-scalar ratio, r<0.44r < 0.44 at 95% confidence (the expected 1σ1 \sigma constraint on rr given the measurement uncertainties is 0.22). We find the measured B-mode power is consistent with the Planck best-fit Λ\LambdaCDM model predictions. Scaling the predicted lensing B-mode power in this model by a factor Alens, the data prefer Alens = 1.17±0.131.17 \pm 0.13. These data are currently the most precise measurements of B-mode power at >320\ell > 320.Comment: 16 pages, 4 figures, Submitted to PR

    Optimal CMB Lensing Reconstruction and Parameter Estimation with SPTpol Data

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    We perform the first simultaneous Bayesian parameter inference and optimal reconstruction of the gravitational lensing of the cosmic microwave background (CMB), using 100 deg2^2 of polarization observations from the SPTpol receiver on the South Pole Telescope. These data reach noise levels as low as 5.8 μ\muK-arcmin in polarization, which are low enough that the typically used quadratic estimator (QE) technique for analyzing CMB lensing is significantly sub-optimal. Conversely, the Bayesian procedure extracts all lensing information from the data and is optimal at any noise level. We infer the amplitude of the gravitational lensing potential to be Aϕ=0.949±0.122A_\phi\,{=}\,0.949\,{\pm}\,0.122 using the Bayesian pipeline, consistent with our QE pipeline result, but with 17\% smaller error bars. The Bayesian analysis also provides a simple way to account for systematic uncertainties, performing a similar job as frequentist "bias hardening," and reducing the systematic uncertainty on AϕA_\phi due to polarization calibration from almost half of the statistical error to effectively zero. Finally, we jointly constrain AϕA_\phi along with ALA_{\rm L}, the amplitude of lensing-like effects on the CMB power spectra, demonstrating that the Bayesian method can be used to easily infer parameters both from an optimal lensing reconstruction and from the delensed CMB, while exactly accounting for the correlation between the two. These results demonstrate the feasibility of the Bayesian approach on real data, and pave the way for future analysis of deep CMB polarization measurements with SPT-3G, Simons Observatory, and CMB-S4, where improvements relative to the QE can reach 1.5 times tighter constraints on AϕA_\phi and 7 times lower effective lensing reconstruction noise.Comment: 27 pages, 14 figures, accompanying software package available at https://cosmicmar.com/CMBLensing.j

    Measurements of B-mode polarization of the cosmic microwave background from 500 square degrees of SPTpol data

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    We report a B-mode power spectrum measurement from the cosmic microwave background (CMB) polarization anisotropy observations made using the SPTpol instrument on the South Pole Telescope. This work uses 500 deg² of SPTpol data, a five-fold increase over the last SPTpol B-mode release. As a result, the bandpower uncertainties have been reduced by more than a factor of two, and the measurement extends to lower multipoles: 52 < ℓ < 2301. Data from both 95 and 150 GHz are used, allowing for three cross-spectra: 95 GHz × 95 GHz, 95 GHz × 150 GHz, and 150 GHz × 150 GHz. B-mode power is detected at very high significance; we find P(BB < 0) = 5.8 × 10⁻⁷¹, corresponding to a 18.1σ detection of power. With a prior on the galactic dust from Planck, WMAP and BICEP2/Keck observations, the SPTpol B-mode data can be used to set an upper limit on the tensor-to-scalar ratio, r < 0.44 at 95% confidence (the expected 1σ constraint on r given the measurement uncertainties is 0.22). We find the measured B-mode power is consistent with the Planck best-fit Λ CDM model predictions. Scaling the predicted lensing B-mode power in this model by a factor A_(lens), the data prefer A_(lens) = 1.17 ± 0.13. These data are currently the most precise measurements of B-mode power at ℓ > 320

    Constraints on cosmological parameters from the 500 deg2 SPTPOL lensing power spectrum

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    We present cosmological constraints based on the cosmic microwave background (CMB) lensing potential power spectrum measurement from the recent 500 deg2 SPTpol survey, the most precise CMB lensing measurement from the ground to date. We fit a flat ΛCDM model to the reconstructed lensing power spectrum alone and in addition with other data sets: baryon acoustic oscillations (BAO), as well as primary CMB spectra from Planck and SPTpol. The cosmological constraints based on SPTpol and Planck lensing band powers are in good agreement when analyzed alone and in combination with Planck full-sky primary CMB data. With weak priors on the baryon density and other parameters, the SPTpol CMB lensing data alone provide a 4% constraint on σ8Ωm0.25=0.593±0.025{\sigma }_{8}{{\rm{\Omega }}}_{m}^{0.25}=0.593\pm 0.025. Jointly fitting with BAO data, we find σ8=0.779±0.023{\sigma }_{8}=0.779\pm 0.023, Ωm=0.3680.037+0.032{{\rm{\Omega }}}_{m}={0.368}_{-0.037}^{+0.032}, and H0=72.02.5+2.1kms1Mpc1{H}_{0}={72.0}_{-2.5}^{+2.1}\,\mathrm{km}\,{{\rm{s}}}^{-1}\,{\mathrm{Mpc}}^{-1}, up to 2σ2\sigma away from the central values preferred by Planck lensing + BAO. However, we recover good agreement between SPTpol and Planck when restricting the analysis to similar scales. We also consider single-parameter extensions to the flat ΛCDM model. The SPTpol lensing spectrum constrains the spatial curvature to be ΩK=0.0007±0.0025{{\rm{\Omega }}}_{K}=-0.0007\pm 0.0025 and the sum of the neutrino masses to be mν<0.23\sum {m}_{\nu }\lt 0.23 eV at 95% C.L. (with Planck primary CMB and BAO data), in good agreement with the Planck lensing results. With the differences in the signal-to-noise ratio of the lensing modes and the angular scales covered in the lensing spectra, this analysis represents an important independent check on the full-sky Planck lensing measurement

    Improving Cosmological Constraints from Galaxy Cluster Number Counts with CMB-cluster-lensing Data: Results from the SPT-SZ Survey and Forecasts for the Future

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    We show the improvement to cosmological constraints from galaxy cluster surveys with the addition of cosmic microwave background (CMB)-cluster lensing data. We explore the cosmological implications of adding mass information from the 3.1 sigma detection of gravitational lensing of the CMB by galaxy clusters to the Sunyaev-Zel'dovich (SZ) selected galaxy cluster sample from the 2500 deg(2) SPT-SZ survey and targeted optical and X-ray follow-up data. In the ACDM model, the combination of the cluster sample with the Planck power spectrum measurements prefers sigma(8) (Omega(m)/0.3)(0.5) = 0.831 +/- 0.020. Adding the cluster data reduces the uncertainty on this quantity by a factor of 1.4, which is unchanged whether the 3.1 sigma CMB-cluster lensing measurement is included or not. We then forecast the impact of CMB-cluster lensing measurements with future cluster catalogs. Adding CMB-cluster lensing measurements to the SZ cluster catalog of the ongoing SPT-3G survey is expected to improve the expected constraint on the dark energy equation of state w by a factor of 1.3 to sigma(w) = 0.19. We find the largest improvements from CMB-cluster lensing measurements to be for sigma(8), where adding CMB-cluster lensing data to the cluster number counts reduces the expected uncertainty on sigma(8) by respective factors of 2.4 and 3.6 for SPT-3G and CMB-S4

    An Improved Measurement of the Secondary Cosmic Microwave Background Anisotropies from the SPT-SZ + SPTpol Surveys

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    We report new measurements of millimeter-wave power spectra in the angular multipole range 200011,0002000 \le \ell \le 11,000 (angular scales 5θ15^\prime \gtrsim \theta \gtrsim 1^\prime). By adding 95 and 150\,GHz data from the low-noise 500 deg2^2 SPTpol survey to the SPT-SZ three-frequency 2540 deg2^2 survey, we substantially reduce the uncertainties in these bands. These power spectra include contributions from the primary cosmic microwave background, cosmic infrared background, radio galaxies, and thermal and kinematic Sunyaev-Zel'dovich (SZ) effects. The data favor a thermal SZ (tSZ) power at 143\,GHz of D3000tSZ=3.42±0.54 μK2D^{\rm tSZ}_{3000} = 3.42 \pm 0.54~ \mu {\rm K}^2 and a kinematic SZ (kSZ) power of D3000kSZ=3.0±1.0 μK2D^{\rm kSZ}_{3000} = 3.0 \pm 1.0~ \mu {\rm K}^2. This is the first measurement of kSZ power at 3σ\ge 3\,\sigma. We study the implications of the measured kSZ power for the epoch of reionization, finding the duration of reionization to be Δzre=1.00.7+1.6\Delta z_{re} = 1.0^{+1.6}_{-0.7} (Δzre<4.1\Delta z_{re}< 4.1 at 95% confidence), when combined with our previously published tSZ bispectrum measurement.Comment: Submitted to ApJ, 16 pages. (revised portions of the introduction and description of bandpower estimation
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