2,247 research outputs found

    catena-Poly[[dichloridozinc(II)]-μ-[1,1′-(butane-1,4-di­yl)diimidazole-κ2 N 3:N 3′]]

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    The title one-dimensional coordination polymer, [ZnCl2(C10H14N4)]n, was synthesized by hydro­thermal methods from ZnCl2 and 1,1′-(butane-1,4-di­yl)diimidazole. The Zn atom is coordinated by two chloride ions and two N atoms from two symmetry-independent organic ligands and shows a distorted tetra­hedral coordination geometry. The 1,1′-(butane-1,4-di­yl)diimidazole ligands are located around two sets of inversion centers and bridge ZnII ions, forming a zigzag polymeric chain. C—H⋯Cl hydrogen bonding results in the formation of a three-dimensional supra­molecular networ

    Case Report: Imaging features of a new type double inferior vena cava malformation and review

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    BackgroundDouble inferior vena cava (DIVC) is a rare vascular malformation. With advances in radiological techniques and diagnosis, more and more types of DIVC were identified and diagnosed. Recognition of the variety of DIVC seen on imaging is essential for subsequent venous interventions.Case presentationA 77-year-old man presented with low back pain with left lower limb pain for 1 month. Scattered petechiae above the skin surface on the left lower leg, especially on the extensor surface, with flaking and mild tingling of the skin, were noted 3 weeks ago. Ultrasound revealed deep vein thrombosis (DVT) in the left lower limb. Computed tomography pulmonary angiography (CTPA) suggested no significant thrombus in the pulmonary artery. Computed tomography venography (CTV) of bilateral lower limbs showed that iliac vein compression syndrome with formation of deep and superficial venous traffic branches in bilateral lower limbs, predominantly on the left side. CTV of the inferior vena cava (IVC) suggested that the left common iliac vein crossed the common iliac artery bifurcation from dorsal to ventral and continued to travel cranially as a ventral vessel, and connected with the ventral IVC anterior to the right common iliac artery. The right common iliac vein extended cephalad as a dorsal vessel, which was narrowed at the level of 4th lumbar vertebra by compression of the hyperplastic bone and the osteophyte. The patient was discharged after right and left common iliac vein angiography and balloon dilation of bilateral common iliac vein.ConclusionThe formation of both ventrally and dorsally aligned DIVC is rarer. It should be clarified the effects of DIVC on DVT formation, and the importance of imaging for preoperative planning

    Phantom Behavior Bounce with Tachyon and Non-minimal Derivative Coupling

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    The bouncing cosmology provides a successful solution of the cosmological singularity problem. In this paper, we study the bouncing behavior of a single scalar field model with tachyon field non-minimally coupled to itself, its derivative and to the curvature. By utilizing the numerical calculations we will show that the bouncing solution can appear in the universe dominated by such a quintom matter with equation of state crossing the phantom divide line. We also investigate the classical stability of our model using the phase velocity of the homogeneous perturbations of the tachyon scalar field.Comment: 15 pages, 8 figures, Accepted for publication in JCAP. arXiv admin note: substantial text overlap with arXiv:1105.496

    Dzyaloshinskii-Moriya Interaction and Spiral Order in Spin-orbit Coupled Optical Lattices

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    We show that the recent experimental realization of spin-orbit coupling in ultracold atomic gases can be used to study different types of spin spiral order and resulting multiferroic effects. Spin-orbit coupling in optical lattices can give rise to the Dzyaloshinskii-Moriya (DM) spin interaction which is essential for spin spiral order. By taking into account spin-orbit coupling and an external Zeeman field, we derive an effective spin model in the Mott insulator regime at half filling and demonstrate that the DM interaction in optical lattices can be made extremely strong with realistic experimental parameters. The rich finite temperature phase diagrams of the effective spin models for fermions and bosons are obtained via classical Monte Carlo simulations.Comment: 7 pages, 5 figure

    Reconstructing the properties of dark energy from recent observations

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    We explore the properties of dark energy from recent observational data, including the Gold Sne Ia, the baryonic acoustic oscillation peak from SDSS, the CMB shift parameter from WMAP3, the X-ray gas mass fraction in cluster and the Hubble parameter versus redshift. The ΛCDM\Lambda CDM model with curvature and two parameterized dark energy models are studied. For the ΛCDM\Lambda CDM model, we find that the flat universe is consistent with observations at the 1σ1\sigma confidence level and a closed universe is slightly favored by these data. For two parameterized dark energy models, with the prior given on the present matter density, Ωm0\Omega_{m0}, with Ωm0=0.24\Omega_{m0}=0.24, Ωm0=0.28\Omega_{m0}=0.28 and Ωm0=0.32\Omega_{m0}=0.32, our result seems to suggest that the trend of Ωm0\Omega_{m0} dependence for an evolving dark energy from a combination of the observational data sets is model-dependent.Comment: 16 pages, 15 figures, To appear in JCA

    Exploring de Sitter Space and Holography

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    We explore aspects of the physics of de Sitter (dS) space that are relevant to holography with a positive cosmological constant. First we display a nonlocal map that commutes with the de Sitter isometries, transforms the bulk-boundary propagator and solutions of free wave equations in de Sitter onto the same quantities in Euclidean anti-de Sitter (EAdS), and takes the two boundaries of dS to the single EAdS boundary via an antipodal identification. Second we compute the action of scalar fields on dS as a functional of boundary data. Third, we display a family of solutions to 3d gravity with a positive cosmological constant in which the equal time sections are arbitrary genus Riemann surfaces, and compute the action of these spaces as a functional of boundary data from the Einstein gravity and Chern-Simons gravity points of view. These studies suggest that if de Sitter space is dual to a Euclidean conformal field theory (CFT), this theory should involve two disjoint, but possibly entangled factors. We argue that these CFTs would be of a novel form, with unusual hermiticity conditions relating left movers and right movers. After exploring these conditions in a toy model, we combine our observations to propose that a holographic dual description of de Sitter space would involve a pure entangled state in a product of two of our unconventional CFTs associated with the de Sitter boundaries. This state can be constructed to preserve the de Sitter symmetries and and its decomposition in a basis appropriate to antipodal inertial observers would lead to the thermal properties of static patch.Comment: LaTeX, v2: references adde

    Dynamic observation and analysis of metabolic response to moxibustion stimulation on ethanol-induced gastric mucosal lesions (GML) rats.

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    Background(#br)Gastric mucosal lesion (GML) is the initiating pathological process in many refractory gastric diseases. And moxibustion is an increasingly popular alternative therapy that prevents and treats diseases. However, there are few published reports about developing pathology of GML and therapeutic mechanism of moxibustion treatment on GML. In this study, we investigated pathology of GML and therapeutic mechanism of moxibustion treatment on GML.(#br)Methods(#br)The male Sprague-Dawley (SD) rats were induced by intragastric administration of 75% ethanol after fasting for 24 h and treated by moxibustion at Zusanli (ST36) and Liangmen (ST21) for 1 day, 4 days or 7 days. Then we applied 1H NMR-based metabolomics to dynamic analysis of metabolic profiles in biological samples (stomach, cerebral cortex and medulla). And the conventional histopathological examinations as well as metabolic pathways assays were also performed.(#br)Results(#br)Moxibustion intervention showed a beneficial effect on GML by modulating comprehensive metabolic alterations caused by GML, including energy metabolism, membrane metabolism, cellular active and neurotransmitters function.(#br)Conclusions(#br)Moxibustion can effectively treat gastric mucosal damage and effectively regulate the concentration of some related differential metabolites to maintain the stability of the metabolic pathway

    A simulation study on the measurement of D0-D0bar mixing parameter y at BES-III

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    We established a method on measuring the \dzdzb mixing parameter yy for BESIII experiment at the BEPCII e+e−e^+e^- collider. In this method, the doubly tagged ψ(3770)→D0D0‾\psi(3770) \to D^0 \overline{D^0} events, with one DD decays to CP-eigenstates and the other DD decays semileptonically, are used to reconstruct the signals. Since this analysis requires good e/πe/\pi separation, a likelihood approach, which combines the dE/dxdE/dx, time of flight and the electromagnetic shower detectors information, is used for particle identification. We estimate the sensitivity of the measurement of yy to be 0.007 based on a 20fb−120fb^{-1} fully simulated MC sample.Comment: 6 pages, 7 figure
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