No abstract available

[en] Endometrial carcinoma is one of the most common malignant tumors of female reproductive system. MRI has become an important examination method for gynecological tumor because of good soft tissue resolution, multi-directional and multi-level imaging. Conventional MRI has important value in the diagnosis and staging of endometrial carcinoma, but there are limitations. MRI has developed from pure morphological and anatomical imaging into functional imaging due to the rapid development of imaging technology. Functional imaging by means of dynamic contrast enhanced MRI and diffusion weighted imaging have great potential in the diagnosis and staging of endometrial carcinoma. The development and application of functional MRI in endometrial carcinoma were reviewed. (authors)

[en] Three new metal–organic complexes Cu[Hbpdc]_2 (1), [Ni(bpdc)(H_2O)]·H_2O (2) and [Ni(H_2bpdc)(H_2O)_2]SO_4 (3) (H_2bpdc=2,2′-bipyridyl-5,5′-dicarboxylic acid) have been hydrothermally prepared and structurally characterized by elemental analyses, IR spectra, powder X-ray diffraction (PXRD) and single-crystal X-ray diffraction. 1 is a 3-D supramolecular architecture formed by hydrogen bonding interactions between carboxyl O atoms and strong face-to-face π⋯π stacking interactions between bipyridyl rings of Hbpdc"− ligands, 2 exhibits an intriguing 2-D sheet constructed from [Ni(bpdc)(H_2O)] units and 3 displays an infinite 1-D chain built by ([Ni(H_2bpdc)(H_2O)_2]"2"+) fragments through SO_4"2"−. Moreover, thermogravimetric (TG) and derivative thermogravimetric (DTG) analyses of 3 have been conducted and the TG curve shows two-stage weight loss between 300 and 950 K and the corresponding apparent activation energies are calculated by Ozawa–Flynn–Wall (OFW) method and Friedman method. The most probable kinetic model function of the dehydration reaction of 3 has been estimated by Coats–Redfern integral method and Achar–Bridly–Sharp differential method. - Graphical abstract: Three metal–organic complexes containing 2,2′-dipyridyl-5,5′-dicarboxylate ligands were synthesized and the thermal decomposition kinetics were investigated. - Highlights: • Metal–organic complexes containing 2,2′-dipyridyl-5,5′-dicarboxylate ligands. • 3-D supramolecular architecture. • Thermal decomposition kinetics

[en] Objective: To explore the feasibility of CTA in the coronary arteries with the double low technology, namely lowkV (100 kV) and low concentration of iodine wcontrast agent (270 mgI/ml). Methods: In the inclusion criteria, 100 patients with coronary artery CTA examination are divided into A, B two groups. Croup B again divided into B1 and B2 group according to the tube voltage and different iodine contrast agent. A group of 30 cases applied the prospective heart switch control, using 100 kV, 270 mgI/ml Visipaque contrast medium, group B applied retrospective heart switch control, including B1 group of 35 cases with 100 kV, 270 mgI/ml Visipaque contrast medium, B2 group of 35 cases with 120 kV, 370 mgI/ml Iopromide contrast agent. Finally, Calonlate the effective radiation dose of groups. Results: The mean effective dose (ED) in group A is (1.32 ± 0.012) mSv, B1 is (5.55 ± 1.04) mSv, B2 group is (10.57 ± 1.07) mSv. Between group A and group B1, group A and group B2 and B1 and B2 group, there is statistically significant. Conclusion: Under the condition of body mass index of ≤ 25.0 kg/m² or less, the application of double low technology, low kV (100 kV), low concentration of iodine contrast agent, can effectively reduce the radiation dose. (authors)

[en] The electronic structure, magnetic and half-metallic properties of transitional metal (TM)-alloyed zinc-blende ZnO and GaAs (TM = Cr, Mn, Fe, Co, Ni) thin films with biaxial strains on the (0 0 1) plane are studied by density functional theory and beyond. Here, we focus on two simple layer-by-layer delta doping structures with the TM substituting along the (1 0 0) planes (type-I) and (0 0 1) planes (type-II). We find that the Fe-, Co- and Ni-alloyed GaAs, Mn- and Fe-alloyed ZnO, and Co-alloyed ZnO(II) show antiferromagnetic (AFM) states, while Ni-alloyed ZnO(I) and Cr-alloyed GaAs show ferromagnetic (FM) coupling independent of the biaxial strain within 25% along the (0 0 1) plane. For the systems of Cr-alloyed ZnO, Co-alloyed ZnO(I), Ni-alloyed ZnO(II) and Mn-alloyed GaAs(I, II), the strain from the substrate will induce a phase transition from AFM to FM states. The Co-alloyed ZnO(I), Ni-alloyed ZnO(I, II) and Cr-alloyed GaAs(I, II) systems are demonstrated to be half-metallic from the generalized gradient approximation (GGA) calculations. The Cr-alloyed ZnO and Mn-alloyed GaAs systems also show robust half-metallicity with a large spin-flip gap by a GGA + U description, although their half-metallicity disappears with the standard GGA description.

[en] The trend toward miniaturization in manufacturing has led to a requirement for micro/nano measuring techniques capable of measuring tiny features on small components. In this paper we propose and demonstrate a novel scheme for micro/nano displacement measurement based on a double-FBG (fiber Bragg grating) sensing structure, a suspended FBG probe stem and a fiber fused micro-ball tip. Such a scheme has some advantages including robustness, sensitivity, small size with large aspect ratio attainable, simplicity and economy. The preliminary experiments showed that the prototype yielded a measurement resolution of 10 nm and a nonlinear error of 150 nm

[en] A new one-dimensional molybdenum oxide compound with manganese-o-phen subunit: [Mn(o-phen)(H₂O)MoO₄]·H₂O (1) (o-phen=o-phenanthroline) was synthesized by the hydrothermal reaction of Na₂MoO₄·2H₂O, MnSO₄·H₂O, oxalic acid, o-phenanthroline (o-phen) and water. Its structure was determined by elemental analyses, ESR spectrum, TG analysis, IR spectrum and single-crystal X-ray diffraction. Compound 1 crystallizes in triclinic system, space group P-1 with a=7.0401(2) A, b=10.4498(2) A, c=10.5720(2) A, α=73.26(7) deg., β=83.34(8) deg., γ=77.33(9) deg., V=725.5089(0) A³, Z=2, and R₁=0.0322 for 2337 observed reflections. Compound 1 exhibits one-dimensional chain structure. The chains are linked up via hydrogen bonding to 2D layers, which are further assembled through π-π stacking interactions to a 3D supermolecular structure

[en] Highlights: • Novel polyurethane hybrids were prepared with silica as inorganic chain extender. • The properties of polyurethane are significantly improved by hybridizing with silica. • Three-roller shear method is efficient to improve the silica dispersion. - Abstract: In this study, novel polyurethane/silica (PU/SiO₂) hybrid materials, prepared without an external crosslinking agent, were developed via the chemical reaction between urethane groups of PU prepolymer and hydroxyl groups at the surfaces of silica. The added inorganic filler-silica thus played the dual roles not only inorganic chain extender but also reinforcing agent in the preparation of the hybrid. Two different blending methods, were compared with respect to the mechanical properties of the PU/SiO₂ hybrid materials: stirring mixing and three-roller shear mixing. The hybridization mechanism was confirmed using Fourier-transform infrared spectroscopy (FT-IR), solid-state ²⁹Si NMR spectroscopy and X-ray diffraction (XRD). The dispersion of silica particles in the PU matrix was investigated by scanning electron microscopy (SEM). Because of the shear effect of three-roller shear process, the size of the silica aggregates tended to be more uniform. The tensile strength and elongation at break of the PU/SiO₂ hybrid were 51 MPa and 590%, respectively, which represent increases of fourfold and 39% compared to those of neat PU. The thermogravimetric analysis (TGA) results for the PU/SiO₂ hybrids indicated greater thermal stabilities and lower decomposition rates after hybridization. This work contributes new insights into the preparation of high-performance PU/SiO₂ hybrids.

[en] This paper investigates a stochastic Gilpin–Ayala model with general Lévy jumps and stochastic perturbation to around the positive equilibrium of corresponding deterministic model. Sufficient conditions for extinction are established as well as nonpersistence in the mean, weak persistence and stochastic permanence. The threshold between weak persistence and extinction is obtained. Asymptotic behavior around the positive equilibrium of corresponding deterministic model is discussed. Our results imply the general Lévy jumps is propitious to population survival when its intensity is more than 0, and some changes profoundly if not. Numerical simulink graphics are introduced to support the analytical findings.

[en] The dynamical properties of a stochastic susceptible-infected epidemic model with Logistic growth are investigated in this paper. We show that the stochastic model admits a nonnegative solution by using the Lyapunov function method. We then obtain that the infected individuals are persistent under some simple conditions. As a consequence, a simple sufficient condition that guarantees the extinction of the infected individuals is presented with a couple of illustrative examples.