A novel series of solution methods for solving nonlinear stiff dynamic problems

Nonlinear Dynamics - A novel type of linear multi-step formulas is proposed for solving initial value problems, such as the problems of multi-body systems and vibration systems and a variety of...     

Mapped WENO schemes based on a new smoothness indicator for Hamilton–Jacobi equations

In this paper, we introduce an improved version of mapped weighted essentially non-oscillatory (WENO) schemes for solving Hamilton–Jacobi equations. To this end, we first discuss new smoothness indicators for WENO construction. Then the new smoothness indicators are combined with the mapping function developed by Henrick et al. (2005) [31]. The proposed scheme yields fifth-order accuracy in smooth regions and sharply resolve discontinuities in the derivatives. Numerical experiments are provided to demonstrate the performance of the proposed schemes on a variety of one-dimensional and two-dimensional problems.     

Two new terpenes from Tripterygium wilfordii

<正>Two new terpenes,wilfornine H(1) and triptobenzene Q(2) were isolated from Tripterygium wilfordii,as well as 11 terpenes. Their structures were elucidated by spectroscopic methods.Compounds 5,9-13 showed significant immunosuppressive activities.     

Combined prostate diffusion tensor imaging and dynamic contrast enhanced MRI at 3T — quantitative correlation with biopsy

The purpose of this work was to compare diagnostic accuracy of Diffusion Tensor Imaging (DTI), dynamic contrast-enhanced magnetic resonance imaging (DCE MRI) and their combination in diagnosing prostate cancer. Twenty-five patients with clinical suspicion of prostate cancer underwent MRI, prior to transrectal ultrasound-guided biopsies. MRI data were correlated to biopsy results. Logistic regression models were constructed for the DTI parameters, DCE MRI parameters, and their combination. The areas under the receiver operator characteristic curves (AUC) were compared between the models. The nonparametric Wilcoxon signed rank test was used for statistical analysis. The sensitivity and specificity values were respectively 81% (74–87%) and 85% (79–90%) for DTI and 63% (55–70%) and 90% (85–94%) for DCE. The combination “DTI or DCE MRI” had 100% (97–100%) sensitivity and 77% (69–83%) specificity, while “DTI and DCE MRI” had 44% (37–52%) sensitivity and 98% (94–100%) specificity. The AUC for DTI+DCE parameters was significantly higher than that for either DTI (0.96 vs. 0.92, P=.0143) or DCE MRI parameters (0.96 vs. 0.87, P=.00187) alone. In conclusion, the combination of DTI and DCE MRI has significantly better accuracy in prostate cancer diagnosis than either technique alone.     

Antibacterial and Miscibility Properties of Chitosan/Collagen Blends

The miscibility, bioactivity, and antibacterial properties of chitosan/collagen specimens were systematically studied. The specimens were prepared by blending collagen and chitosan with varying deacetylation degrees in solutions; the collagen molecules had been extracted from pigskins using the acid swelling-pepsin digestion method. To understand the miscibility properties of collagen and chitosan molecules, the intrinsic viscosity and differential scanning calorimetry analysis of collagen, chitosan, and collagen/chitosan specimens were performed. The instrinsic viscosity measurements suggested that chitosan and collagen molecules with varying deacetylation degrees were miscible at molecular level for all compositions and degrees of deacetylation of chitosan/collagen mixture solutions prepared in this study. Fourier transform infrared analyses suggested that the percentage of preserved triple helix structures present in collagen molecules in collagen/chitosan specimens decreased with increasing chitosan contents, since the ratios of peak absorbance at 1239 cm^?1 of amide III and 1455 cm^?1 of C?H bending of collagen/chitosan specimens decreased significantly with increase in their chitosan contents. Abnormally high denaturation temperatures (T_d) were observed as the chitosan contents of collagen/chitosan specimens reached 40 wt%, at which T_d of collagen molecules was even higher than that of the corresponding pure chitosan molecules with varying deacetylation degrees. The antibacterial activity of collagen/chitosan blends increased consistently with increasing deacetylation degrees and concentrations of chitosan molecules in collagen/chitosan solutions. Possible explanations for these interesting thermal denaturation, antibacterial, and miscibility properties of chitosan/collagen specimens are reported.     

Rotationally resolved state-to-state photoelectron study of zirconium monoxide cation (ZrO+)

Using two-colour visible (Vis)–ultraviolet (UV) photoionisation and pulsed field ionisation–photoelectron (PFI–PE) methods, we have obtained cleanly rotationally resolved photoelectron spectra for ZrO⁺(X ²Δ_3/2,5/2; v⁺ = 0, 1, and 2). The rotation assignment of these state-to-state Vis–UV–PFI–PE spectra has allowed the unambiguous determination of the ground state term symmetry for ZrO⁺(X) to be ²Δ_3/2, and the adiabatic ionisation energy of ⁹⁰Zr¹⁶O, IE(⁹⁰Zr¹⁶O) = 54,948.3(8) cm^?1 [6.81272(10) eV]. The symmetry of the ionic ZrO⁺(X ²Δ_3/2) ground state determined here disagrees with that reported in previous experiments. The rotational and vibrational constants determined in this experiment for the ionic ⁹⁰Zr¹⁶O⁺(X ²Δ_3/2) ground state are: B_e⁺ = 0.4343(8) cm^?1 and α_e⁺ = 0.0019(5) cm^?1, and ω_e⁺ = 991.2(8) cm^?1 and ω_e⁺x_e⁺ = 3.5(8) cm^?1; and those for the ionic ⁹⁰Zr¹⁶O⁺(X ²Δ_5/2) excited spin-orbit state are: B_e⁺ = 0.4357(6) cm^?1 and α_e⁺ = 0.0022(4) cm^?1, and ω_e⁺ = 991.9(8) cm^?1 and ω_e⁺x_e⁺ = 3.6(8) cm^?1, respectively. Based on the latter B_e⁺ value, the equilibrium bond distances are determined to be r_e⁺ = 1.691(2) Å for ⁹⁰Zr¹⁶O⁺(X ²Δ_3/2) and r_e⁺ = 1.688(1) Å for ⁹⁰Zr¹⁶O⁺(X ²Δ_5/2). The IE(ZrO) along with the spectroscopic constants obtained here are valuable for benchmarking the ab initio quantum chemical calculations for energetic and structural predictions of ZrO/ZrO⁺.