1,688 research outputs found

    Pb(II) and Mn(II) Supermolecular Polymers of Bipy and (4-Chlorophenyloxy) Acetate Anions: Syntheses, Structure and Fluorescence Properties

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    Two new supermolecular polymers of the formula [Pb4L8(2,2’-bipy)4] 1 and [MnL2(4,4’-bipy)] 2 [HL = (4-chlorophenyloxy)acetic acid] have been synthesized and characterized by X-ray single crystal diffraction analysis, elemental analysis, fluorescence spectroscopy method and electrochemical analysis. Complex 1 is a multinuclear dimmer in which four Pb ions are linked together by the L ligands. In complex 2, each carboxyl of L bridges two Mn ions to form infinite Mn–O–C-Orods. Both in complex 1 and complex 2, π–π stacking and van der Waals’ interactions make the two complexes stable, 3-D, supermolecular polymers. This work will contribute to the design and synthesis of fluorescent, supramolecular polymers.Keywords: Supermolecular polymers, fluorescence, 4-chlorophenyloxyacetic aci

    Determination of Chemical Constituents of the Marine Pulmonate Slug, Paraoncidium reevesii

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    Purpose: To isolate and identify the chemical components of Paraoncidium reevesii.Methods: Silica gel column chromatography was used to isolate the components from petroleum ether and ethyl acetate fractions of the acetone extract, and the structures of the compounds were derived from 1H-nuclear magnetic resonance (1H-NMR), 13C-nuclear magnetic resonance (13C-NMR) and mass spectrometry (MS) analyses and also with the aid of literature data for authenticated samples.Results: Cholesterol (1), baconipyrone D (2), chimyl alcohol (3), batyl alcohol (4), á-monpalmitin (5), stearic acid (6), 3-indolecarboxylic acid (7), uracil (8), thymine (9), uridine (10), thymidine (11) were isolated from the marine slug (Paraoncidium reevesii).Conclusion: All the isolated compounds are being reported here for Paraoncidium reevesii for the first time. The results provide base data for further study of the Onchidiidae as a Chinese traditional remedy for asthma and athlete’s foot.Keywords: Mollusk, Paraoncidium reevesii, Baconipyrone D, Batyl alcohol, Chimyl alcohol Onchidiidae, Marine Pulmonate, Slug, Asthma, Athlete’s foo

    Protective antitumor activity induced by a fusion vaccine with murine beta-defensin2 and VE-cadherin in mouse models

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    Targeting angiogenesis is an effective strategy for anticancer therapy. The vascular endothelialcadherin (VE-cad) regulated angiogenesis is a potential target for anti-angiogenesis. Here, we develop a fusion vaccine plasmid DNA pSec-MBD2-VE-cad from VE-cad and murine beta defensin2 (MBD2) to induce immunity for cancer therapy. The expression and biological activity of fusion protein were detected in vitro. Anti-tumor effects and inhibition of angiogenesis via pSec-MBD2-VE-cad were investigated in mice model. The anti-VE-cad antibodies and cytotoxic T lymphocyte (CTL) responses were analyzed. Inhibition of tumor-induced angiogenesis and prolonged survival were shown in mice challenged with murine colon adenocarcinoma (CT26) or Murine fibrosarcoma cell line (MethA) after immunization with the fusion vaccine. Moreover, VE-cad-specific antibodies and specific T cell cytotoxicity were detected. The fusion vaccine based on self immune peptide Murine beta defensin2 (MBD2) and self antigen mVE-cad could induce autoimmunity and inhibit tumor growth, and thus there may be potential applications in cancer therapy

    Dipole-Quadrupole Theory of Surface Enhanced Infrared Absorption and Appearance of Forbidden Lines in the SEIRA Spectra of Symmetrical Molecules

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    The paper presents main aspects of the Dipole-Quadrupole theory of Surface Enhanced Infrared Absorption (SEIRA). It is pointed out the possibility of appearance of the lines, caused by totally symmetric vibrations transforming after the unit irreducible representation, which are forbidden in usual infrared absorption spectra in molecules with sufficiently high symmetry. Observation of such lines in the SEIRA spectra of diprotonated and ethylene, adsorbed on and on mordenites is pointed out. The results well agree with our ideas about surface enhanced optical processes, based on the conception of a strong quadrupole light-molecule interaction, which allows us to develop the SERS and SEHRS theories.Comment: 15 pages,3 figures, 1 tabl

    Measurements of branching fractions for inclusive K0~/K0 and K*(892)+- decays of neutral and charged D mesons

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    Using the data sample of about 33 pb-1 collected at and around 3.773 GeV with the BES-II detector at the BEPC collider, we have studied inclusive K0~/K0 and K*(892)+- decays of D0 and D+ mesons. The branching fractions for the inclusive K0~/K0 and K*(892)- decays are measured to be BF(D0 to K0~/K0 X)=(47.6+-4.8+-3.0)%, BF(D+ to K0~/K0 X)=(60.5+-5.5+-3.3)%, BF(D0 to K*- X)=(15.3+- 8.3+- 1.9)% and BF(D+ to K*- X)=(5.7+- 5.2+- 0.7)%. The upper limits of the branching fractions for the inclusive K*(892)+ decays are set to be BF(D0 to K*+ X)<3.6% and BF(D+ to K*+ X) <20.3% at 90% confidence level

    Direct Measurements of the Branching Fractions for Inclusive K±K^\pm and Inclusive Semileptonic Decays of D+D^+ and D0D^0 Mesons

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    With singly-tagged Dˉ\bar D samples selected from the data collected at and around 3.773 GeV with the BESII detector at the BEPC collider, we have measured the branching fractions for the inclusive K±K^\pm decays of D+D^+ and D0D^0 mesons, which are BF(D+→K−X)=(24.7±1.3±1.2)BF(D^+\to K^-X) = (24.7 \pm 1.3 \pm 1.2)%, BF(D+→K+X)=(6.1±0.9±0.4)BF(D^+\to K^+X) = (6.1 \pm 0.9 \pm 0.4) %, BF(D0→K−X)=(57.8±1.6±3.2)BF(D^0\to K^-X) = (57.8 \pm 1.6 \pm 3.2) % and BF(D0→K+X)=(3.5±0.7±0.3)BF(D^0\to K^+X) = (3.5 \pm 0.7 \pm 0.3) %, respectively. We have also measured the branching fractions for the inclusive semileptonic decays of D+D^+ and D0D^0 mesons to be BF(D+→e+X)=(15.2±0.9±0.8)BF(D^+ \to e^+ X)=(15.2 \pm 0.9 \pm 0.8)% and BF(D0→e+X)=(6.3±0.7±0.4)BF(D^0 \to e^+ X) =(6.3 \pm 0.7 \pm 0.4) %. These yield the ratio of their partial widths to be Γ(D+→e+X)/Γ(D0→e+X)=0.95±0.12±0.07\Gamma(D^+ \to e^+X)/\Gamma(D^0 \to e^+X)=0.95 \pm 0.12 \pm 0.07.Comment: 6 pages, 5 figure

    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/ψ→ΛΛˉπ0)<6.4×10−5{\cal B}(J/\psi \to \Lambda \bar{\Lambda}\pi^0)<6.4\times 10^{-5} and B(ψ(2S)→ΛΛˉπ0)<4.9×10−5{\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/ψ→ΛΛˉηJ/\psi \to \Lambda \bar{\Lambda}\eta is observed for the first time, and its branching fraction is measured to be B(J/ψ→ΛΛˉη)=(2.62±0.60±0.44)×10−4{\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)<1.2×10−4{\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+π−barΛ\Sigma^+ \pi^- bar{\Lambda} and Σˉ−π+Λ\bar{\Sigma}^- \pi^+ \Lambda are also reported, and the sum of these branching fractions is determined to be B(J/ψ→Σ+π−Λˉ+c.c.)=(1.52±0.08±0.16)×10−3{\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

    First observation of ψ(2S)→pnˉπ−+c.c.\psi(2S) \to p \bar{n} \pi^- +c.c.

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    Using 14 million ψ(2S)\psi(2S) events collected with the Beijing Spectrometer (BESII) at the Beijing Electron-Positron Collider, the branching fractions of ψ(2S)\psi(2S) decays to pnˉπ−p \bar{n} \pi^- and pˉnπ+\bar{p} n \pi^+ and the branching fractions of the main background channels ψ(2S)→pnˉπ−π0\psi(2S) \to p \bar{n} \pi^-\pi^0, ψ(2S)→γχc0→γpnˉπ−\psi(2S) \to \gamma\chi_{c0} \to \gamma p \bar{n} \pi^-, ψ(2S)→γχc2→γpnˉπ−\psi(2S) \to \gamma\chi_{c2} \to \gamma p \bar{n} \pi^-, and ψ(2S)→γχcJ→γpnˉπ−π0\psi(2S) \to \gamma \chi_{cJ} \to \gamma p \bar{n} \pi^- \pi^0 are determined. The contributions of the N∗N^{\ast} resonances in ψ(2S)→pnˉπ−+c.c.\psi(2S) \to p \bar{n} \pi^- +c.c. are also discussed.Comment: 19 pages, 8 figures, add vertex requirement systematic erro
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