2,880 research outputs found

    Patrick-Murray Administration Celebrates Grand Opening of Old Colony Housing Development

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    <p>This case report presents the use of near-infrared fluorescence (NIRF) imaging using indocyanine green (ICG) and its potential for the evaluation of soft tissue viability in a traumatic case. Standard implementation of this novel imaging modality might decrease the number of surgical debridement procedures in complex traumatic wounds.</p

    Innervation of a prefabricated flap: a new experimental model

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    Introduction. Flap innervation by neoaxonogenesis is a promising field of investigation. The authors evaluated the possibility of innervating an acellular collagen scaffold as component of a potential prefabricated flap. Materials and Methods. Collagen matrix sheets were implanted around the femoral bundle of a murine model to produce two flaps on proximal and distal nerve stumps based on a flow-through model. After thirty days, nerve regeneration and integration into the collagen matrix were evaluated. The specimens were microscopically analyzed to study Schwann cell colonization and axonal integration with the matrix. Axonal count and density were assessed and statistically evaluated. Results. Qualitative structural and ultrastructural evaluation indicated integration, with axonal fibers merged within the collagen matrix, along with a newly formed vascular network on the proximal flap. Wallerian degeneration occurred inside the distal chamber. Axonal count and density did not show statistically significant differences between the nerve inside the proximal flap and the control side. Conclusions. Innervation of an acellular matrix can be obtained by direct nerve stump implantation. The flow-through system was relatively easy to build and reliable to provide adequate blood supply. The collagen scaffold may be a promising support or further studies of preinnervated microsurgical flaps

    Terahertz generation in Czochralski grown periodically poled Mg:Y:LiNbO3 via optical rectification

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    Using a canonical pump-probe experimental technique, we studied the terahertz (THz) waves generation and detection via optical rectification and mixing in Czochralski-grown periodically poled Mg:Y:LiNbO3 (PPLN) crystals. THz waves with frequencies at 1.37 THz and 0.68 THz as well as 1.8 THz were obtained for PPLN with nonlinear grating periods of 0.03 and 0.06 mm, respectively. A general theoretical model was developed by considering the dispersion and damping of low frequency phonon-polariton mode. Our results show that THz waves are generated in forward and backward directions via pumping pulse rectification. The generated THz waves depend on the spectral shape of the laser pulses, quasi-phase mismatches and dispersion characteristics of a crystal.Comment: 25 pages, 4 figure

    Ground-Based Multiangle Solar-Induced Chlorophyll Fluorescence Observation and Angular Normalization for Assessing Crop Productivity

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    Solar-induced chlorophyll fluorescence (SIF) provides remotely sensible signals for monitoring gross primary production (GPP). Ground-based multiangle observations of both red and far-red SIF above wheat and maize canopies were conducted to examine angular effects on SIF. With these new measurements, we were able for the first time to refine and apply an algorithm developed for angular normalization of both red and far-red SIF measurements. The angular normalization improved the correlation of SIF with GPP derived from eddy covariance measurements at the instantaneous scale (1 min), with increases of the diurnal coefficients of determination (of sunlit SIF with GPP) up to 0.21 for far-red SIF and 0.3 for red SIF based on analysis on 6 sunny days. The improvement was slightly smaller for far-red SIF than for red SIF, attributing to that the observed angular variation of SIF in the red band was greater than that in the far-red band due to weaker multiple scattering in the red band in the canopy. In addition, at the hourly time scale, far-red sunlit SIF shows its advantage to track GPP for heterogonous canopies, while angular normalization of red SIF is effective for homogeneous canopies. In comparison with another angular normalization method based on the escape ratio using datasets over both wheat and maize canopies, the two kinds of method show similar ability to improve the correlation between SIF and GPP, while the results suggest a limitation of SIF in estimating GPP for dense canopies where the fraction of shaded leaves are large.The data supporting the results can be accessed through the open repository Figshare (https://doi. org/10.6084/m9.figshare.13011470.v2)National Natural Science Foundation of China (NSFC). Grant Numbers: 41671343, 42071392: 42071388: 42001271: 41701393Peer reviewe

    Gap structure in the electron-doped Iron-Arsenide Superconductor Ba(Fe0.92Co0.08)2As2: low-temperature specific heat study

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    We report the field and temperature dependence of the low-temperature specific heat down to 400 mK and in magnetic fields up to 9 T of the electron-doped Ba(Fe0.92Co0.08)2As2 superconductor. Using the phonon specific heat obtained from pure BaFe2As2 we find the normal state Sommerfeld coefficient to be 18 mJ/mol.K^2 and a condensation energy of 1.27 J/mol. The temperature dependence of the electronic specific heat clearly indicate the presence of the low-energy excitations in the system. The magnetic field variation of field-induced specific heat cannot be described by single clean s- or d-wave models. Rather, the data require an anisotropic gap scenario which may or may not have nodes. We discuss the implications of these results.Comment: New Journal of Physics in press, 10 pages, 5 figure

    Measurement of the chi_{c2} Polarization in psi(2S) to gamma chi_{c2}

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    The polarization of the chi_{c2} produced in psi(2S) decays into gamma chi_{c2} is measured using a sample of 14*10^6 psi(2S) events collected by BESII at the BEPC. A fit to the chi_{c2} production and decay angular distributions in psi(2S) to gamma chi_{c2}, chi_{c2} to pi pi and KK yields values x=A_1/A_0=2.08+/-0.44 and y=A_2/A_0=3.03 +/-0.66, with a correlation rho=0.92 between them, where A_{0,1,2} are the chi_{c2} helicity amplitudes. The measurement agrees with a pure E1 transition, and M2 and E3 contributions do not differ significantly from zero.Comment: 6 pages, 4 figures, 1 tabl

    Measurement of \psip Radiative Decays

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    Using 14 million psi(2S) events accumulated at the BESII detector, we report first measurements of branching fractions or upper limits for psi(2S) decays into gamma ppbar, gamma 2(pi^+pi^-), gamma K_s K^-pi^++c.c., gamma K^+ K^- pi^+pi^-, gamma K^{*0} K^- pi^+ +c.c., gamma K^{*0}\bar K^{*0}, gamma pi^+pi^- p pbar, gamma 2(K^+K^-), gamma 3(pi^+pi^-), and gamma 2(pi^+pi^-)K^+K^- with the invariant mass of hadrons below 2.9GeV/c^2. We also report branching fractions of psi(2S) decays into 2(pi^+pi^-) pi^0, omega pi^+pi^-, omega f_2(1270), b_1^\pm pi^\mp, and pi^0 2(pi^+pi^-) K^+K^-.Comment: 5 pages, 4 figure

    Measurements of J/ψJ/\psi and ψ(2S)\psi(2S) decays into ΛΛˉπ0\Lambda \bar{\Lambda}\pi^0 and ΛΛˉη\Lambda \bar{\Lambda}\eta

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    Using 58 million J/ψJ/\psi and 14 million ψ(2S)\psi(2S) events collected by the BESII detector at the BEPC, branching fractions or upper limits for the decays J/ψJ/\psi and ψ(2S)ΛΛˉπ0\psi(2S) \to \Lambda \bar{\Lambda}\pi^0 and ΛΛˉη\Lambda \bar{\Lambda}\eta are measured. For the isospin violating decays, the upper limits are determined to be B(J/ψΛΛˉπ0)<6.4×105{\cal B}(J/\psi \to \Lambda \bar{\Lambda}\pi^0)<6.4\times 10^{-5} and B(ψ(2S)ΛΛˉπ0)<4.9×105{\cal B}(\psi(2S) \to \Lambda \bar{\Lambda}\pi^0)<4.9\times 10^{-5} at the 90% confidence level. The isospin conserving process J/ψΛΛˉηJ/\psi \to \Lambda \bar{\Lambda}\eta is observed for the first time, and its branching fraction is measured to be B(J/ψΛΛˉη)=(2.62±0.60±0.44)×104{\cal B}(J/\psi \to \Lambda \bar{\Lambda}\eta)=(2.62\pm 0.60\pm 0.44)\times 10^{-4}, where the first error is statistical and the second one is systematic. No ΛΛˉη\Lambda \bar{\Lambda}\eta signal is observed in ψ(2S)\psi(2S) decays, and B(ψ(2S)ΛΛˉη)<1.2×104{\cal B}(\psi(2S) \to \Lambda \bar{\Lambda}\eta)<1.2\times 10^{-4} is set at the 90% confidence level. Branching fractions of J/ψJ/\psi decays into Σ+πbarΛ\Sigma^+ \pi^- bar{\Lambda} and Σˉπ+Λ\bar{\Sigma}^- \pi^+ \Lambda are also reported, and the sum of these branching fractions is determined to be B(J/ψΣ+πΛˉ+c.c.)=(1.52±0.08±0.16)×103{\cal B}(J/\psi \to \Sigma^+\pi^- \bar{\Lambda} + c.c.)=(1.52\pm 0.08\pm 0.16)\times 10^{-3}.Comment: 7 pages, 10 figures. Phys.Rev.D comments considere

    Partial wave analysis of J/psi to p pbar pi0

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    Using a sample of 58 million J/ψJ/\psi events collected with the BESII detector at the BEPC, more than 100,000 J/ψppˉπ0J/\psi \to p\bar p \pi^0 events are selected, and a detailed partial wave analysis is performed. The branching fraction is determined to be Br(J/ψppˉπ0)=(1.33±0.02±0.11)×103Br(J/\psi \to p \bar p \pi^0)=(1.33 \pm 0.02 \pm 0.11) \times 10^{-3}. A long-sought `missing' NN^*, first observed in J/ψpnˉπJ/\psi \to p \bar n \pi^-, is observed in this decay too, with mass and width of 20404+3±252040_{-4}^{+3}\pm 25 MeV/c2^2 and 2308+8±52230_{-8}^{+8}\pm 52 MeV/c2^2, respectively. Its spin-parity favors 3/2+{3/2}^+. The masses, widths, and spin-parities of other NN^* states are obtained as well.Comment: Add one author nam
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