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The Kelvin–Helmholtz instability on the ionopause of Venus with different density ratios and magnetic Reynolds numbers has been simulated numerically by using the magnetohydrodynamics equations. For the special case of a Venus-like planet, the plasma density increases from the magnetosheath to the ionosphere. The numerical simulation shows that the density increasing toward the planet has more important effects than the magnetic Reynolds number on the Kelvin–Helmholtz instability. And during the evolution of the Kelvin–Helmholtz instability, there are three different phases, the linear growth phase, followed by a nonlinear phase with vortex-like structure, and finally, the turbulent phase. During the nonlinear evolution of the Kelvin–Helmholtz instability, the spatial scale of the vortex has a width of about ∼ 12 a , where a is the half width of the shear layer located at the Venusian ionopause. For each phase, the vorticity of the system also has different characteristics. Supersonic flow could appear at the position where the vorticity is stronger in both nonlinear and turbulent phases. [ABSTRACT FROM AUTHOR]

The radiative and Auger decay processes of K-shell ionized Np ions are studied theoretically using the flexible atomic code (FAC). Relativistic effects, Breit interaction, QED corrections and nuclear finite mass and volume effects are considered systematically. The resulting calculated K x-rays and Auger spectra of Np are compared with the measured spectra emitted after the electron-capture (EC)-decay of mass-separated 237Pu. The general consistency between theory and experiment is good; the relative intensities and relative positions of the peaks in the measured spectra are reproduced with good accuracy, in spite of the existence of different ways to produce the primary K-shell vacancy, enabling identification of the observed structure in the experimental spectra. We find that most of the radiative transition rates are greater than the Auger transition rates, and the latter decrease rapidly with the transfer of initial vacancies to the outer shell. [ABSTRACT FROM AUTHOR]

Abstract: The transition energy shifts of the Kα, Kβ and Kγ X-rays resulted from addition vacancies in L-shell for atoms with 13⩽ Z ⩽90 have been calculated systematically, by using the Flexible Atomic Code (FAC), in which the Breit interaction, QED corrections and nuclear finite mass effects are also considered. It is shown by means of concrete figures that the overall agreement among the present results, theoretical results of other authors as well as a large body of measured ones was excellent. Contrary to other discussions, we found that the energy shifts of the Kα and Kβ satellites did not varies absolutely linearly with Z, the contributions of the Z 2 term cannot be neglected, and the energy differences between neighboring L satellites were not equal. Three simple empirical formulae for estimating the energy shifts of the Kα, Kβ and Kγ X-ray satellites for any atom with any number of L-shell vacancies were put forward. They will be useful in qualitative interpretation of various K X-ray spectra and better understanding of the collision processes. [Copyright &y& Elsevier]

Three novel asymmetric ligands, 3-(pyridine-2-yl)-5,6-diphenyl-as-triazine (pdtb), 3-(pyridine-2-yl)-as-triazino[5,6-f]acenaphthylene (pdta) and 3-(pyridine-2-yl)-as-triazino[5,6-f]phenanthroline (pdtp) and their cobalt(III) complexes have been synthesized and characterized. Binding of the three complexes with calf thymus DNA (CT-DNA) has been investigated by spectroscopic methods, viscosity, cyclic voltammetry, and electrophoresis measurements. The experimental results indicate that the size and shape of the intercalated ligand have a marked effect on the binding affinity of complexes to CT-DNA. Complexes 2 and 3 have also been found to promote cleavage of plasmid pBR322 DNA from the supercoiled form I to the open circular form II upon irradiation. [Copyright &y& Elsevier]

Two asymmetric tridentate copper(II) complexes, [Cu(dppt)Cl2] · 0.25H2O (1) (dppt=3-(1,10-phenanthrolin-2-yl)-5,6-diphenyl-as-triazine) and [Cu(pta)Cl2] (2) (pta=3-(1,10-phenanthrolin-2-yl)-as-triazino[5,6-f]acenaphthylene), have been prepared and characterized by elemental analysis, IR and Fast atomic bombardment mass spectra. Complex 1 has also been structurally characterized. The complexes exist as distorted square pyramid with five co-ordination sites occupied by the tridentate ligand and the two chlorine anions. DNA interaction studies suggest that the ligand planarity of the complex has a significant effect on DNA binding affinity increasing in the order [Cu(dppt)Cl2] < [Cu(pta)Cl2]. In the presence of ascorbate or glutathione, the two complexes are found to cause significant cleavage of double-strand pBR 322 DNA and [Cu(pta)Cl2] exhibited the higher cleaving efficiency. [Copyright &y& Elsevier]

We systematically study the decay properties of the K-shell excited F-like ions with 10≤ Z ≤36 based on the multiconfiguration Dirac-Fock method. The Breit interaction, the QED corrections and the nuclear finite mass effects are also considered as perturbation. Auger transition rates, radiative, Auger and natural widths, as well as fluorescence and Auger yields for K-shell excited F-like ions are presented. It is shown by means of concrete figures that the decay properties change significantly with the increase of the atomic number Z; the Auger rate is overtaken at Z = 30 by the radiative decay rate. Several fitting formulae for the radiative and Auger widths and the fluorescence yields have been evaluated which is expected to be useful in plasma analysis and plasma modeling. [ABSTRACT FROM AUTHOR]

For the harmonic signal extraction from chaotic interference, a harmonic signal extraction method is proposed based on synchrosqueezed wavelet transform (SWT). First, the mixed signal of chaotic signal, harmonic signal, and noise is decomposed into a series of intrinsic mode-type functions by synchrosqueezed wavelet transform (SWT) then the instantaneous frequency of intrinsic mode-type functions is analyzed by using of Hilbert transform, and the harmonic extraction is realized. In experiments of harmonic signal extraction, the Duffing and Lorenz chaotic signals are selected as interference signal, and the mixed signal of chaotic signal and harmonic signal is added by Gauss white noises of different intensities. The experimental results show that when the white noise intensity is in a certain range, the extracting harmonic signals measured by the proposed SWT method have higher precision, the harmonic signal extraction effect is obviously superior to the classical empirical mode decomposition method. [ABSTRACT FROM AUTHOR]

The Kelvin-Helmholtz (KH) waves have been frequently observed during the northward interplanetary magnetic field (IMF) but have been much less frequently observed during the southward IMF. Here, we performed a 3D MHD simulation of a KH wave to investigate the evolution of KH instability under the pure southward IMF condition. In the linear phase of KH instability, there are almost no jet flows along northward and southward. In the nonlinear growth phase, the width of the KH vortex is about ∼ 12 λ , and the duration time of the KH vortex is about ∼ 20 t A . Moreover, the obvious jet flows whose peak V z value is about ∼ 0.5 V A are distributed in both the spine region and the edge of the KH vortex. [ABSTRACT FROM AUTHOR]

Cationic meso(4- N-methylpyridyl)-based metallocorroles, μ-oxo iron corrole dimer ( 1b) and manganese corrole monomer ( 2b), were synthesized and characterized. The interactions of these two metal corrole complexes with CT-DNA were studied by UV-visible, fluorescence and circular dichroism spectroscopic methods, as well as by viscosity measurements. The results revealed that 1b interacts with CT-DNA in a difunctional binding mode, i.e. non-classical intercalation and outside groove binding with H-aggregation, while 2b can interact with CT-DNA via an outside groove binding mode only. The binding constants Kb of 1b and 2b were 4.71 × 105 m−1 and 2.17 × 105 m−1, respectively, indicating that 1b can bind more tightly to CT-DNA than 2b. Furthermore, both complexes may cleave the supercoiled plasmid DNA efficiently in the presence of or tert-butyl hydroperoxide (TBHP), albeit 1b exhibited a little higher efficiency. The inhibitor tests suggested that singlet oxygen and high-valent (oxo)iron(VI) corrole or (oxo)manganese(V) corrole might be the active intermediates responsible for the oxidative DNA scission. Copyright © 2014 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

• The fully relativistic method for treating the PI process is developed. • Good agreement with theory and experiments. • Multipole effects on the cross section and alignment after PI are assessed. On the basis of the fully relativistic Dirac-Fock treatment of single ionization by a linearly polarized photon with regard to the E 1, M 1, E 2, M 2, and E 3 multipoles of the radiative field as well as their interference, we have assessed the influence of multipole effects on the cross sections and alignment parameters A 20 and A 22 of the residual ions, taking the 3 p 3/2 and 3 d 3/2 vacancies of selected Zn and Zn-like Kr6+, Cd18+, and Xe24+ ions as examples. Starting from the most general method of density matrix theory, we carried out specific analytic expressions in terms of the reduced matrix elements of multipole fields, corresponding to different ion-core states. It is shown that the multipole contributions to the photoionization cross sections can be considerable, the character of which becomes more evident as the incident energy and/or atomic number increases. These dramatic influences also lead to a remarkable increase in the alignment parameter A 20 of the residual ions, yet virtually independent of the nuclear charge for A 22. The present results in Coulomb gauge and Babushkin gauge excellently agreed with each other, suggesting that there is a high degree of convergence achieved in this study. Comparison of our results with experimental data and other theoretical predictions, when available, is made. [ABSTRACT FROM AUTHOR]

Breast cancer is known as the most prevalent cancer in women worldwide, and has an undeniable negative impact on public health, both physically, and mentally. This study aims to investigate the effects of toll‐like receptor 4 (TLR4) gene silencing on proliferation and apoptosis of human breast cancer cells to explore for a new theoretical basis for its treatment. TLR4 small interference RNA (siRNA) fragment recombinant plasmids were constructed, including TLR4 siRNA‐1, TLR4 siRNA‐2, and TLR4 siRNA‐3. Human breast cancer MCF‐7 and MDA‐MB‐231 cells were assigned into blank, negative control (NC), TLR4 siRNA‐1, TLR4 siRNA‐2, and TLR4 siRNA‐3 groups. MCF‐7 and MDA‐MB‐231 cell growth was detected by MTT assay. Apoptosis and cell cycle were determined by flow cytometry. Reverse transcription quantitative polymerase chain reaction (RT‐qPCR) and Western blot analysis were conducted to determine the expression of TLR4, CDK4, cyclin D1, Livin, Bcl‐2, p53, c‐FLIP, and caspase‐3. In comparison with the NC and blank groups, the TLR4 siRNA‐1, TLR4 siRNA‐2, and TLR4 siRNA‐3 groups showed decreased the expression of TLR4, inhibited proliferation of MCF‐7 and MDA‐MB‐231 cells and promoted MCF‐7 and MDA‐MB‐231 cell apoptosis, and the cells were blocked in G1 phase. In comparison with the NC and blank groups, in the TLR4 siRNA‐1, TLR4 siRNA‐2, and TLR4 siRNA‐3 groups, siRNA‐TLR4 significantly increased expression of p53 and caspase‐3 in MCF‐7 and MDA‐MB‐231 cells, while it decreased the expressions of CDK4, cyclinD1, Livin, Bal‐2, and c‐FLIP. The study demonstrates that TLR4 gene silencing inhibits proliferation and induces apoptosis of MCF‐7 and MDA‐MB‐231 cells. TLR4 gene silencing inhibits proliferation and induces apoptosis of MCF‐7 and MDA‐MB‐231 cells. [ABSTRACT FROM AUTHOR]

Highlights • Hyperfine structure and radiative transition of C-like Fe, Co and Ni are studied. • Electron correlation effect are investigated in detail. • Influences of Breit and QED effect on energies are studied. • The radiative spectra may provide theoretical support for experimental study. Abstract Energy levels, hyperfine structure and 2s-2p radiative transition processes of C-like Fe, Co and Ni are studied by performing multiconfiguration Dirac–Hartree–Fock method using the fully relativistic codes GRASP2K. Electron correlation effect on the energies, hyperfine structure constants and radiative transition rates are investigated in detail. Influences of Breit and quantum electrodynamics (QED) effect on energies are studied. Good agreements are found between the results in this work and experimental data. The radiative spectra of the excited states 1s22s2p3 and 1s22p4 of C-like Fe, Co and Ni may provide theoretical support for further experimental study. Since Fe, Co and Ni are important constituent part of experimental apparatus (such as EBIT), the data in this work have important application value for experimental application. [ABSTRACT FROM AUTHOR]

Polytetrafluoroethylene (PTFE) was irradiated with protons in a ground-based simulation facility to study the effects of proton irradiation on the structural and tribological properties of PTFE. The structural changes were characterized by X-ray photoelectron spectroscopy (XPS) and attenuated total-reflection FTIR (ATR-FTIR), while the tribological properties were evaluated by friction and wear tests. It was found that proton irradiation induced the degradation of PTFE molecular chains, resulting in the increase of C concentration and the decrease in F concentration on the sample surfaces, and the surface chemical structure and morphology of the samples changed, which affected the friction coefficient and decreased the wear rate of the specimens as the friction and wear tests revealed. [ABSTRACT FROM AUTHOR]

Selenium isotopes are becoming an important paleoenvironmental proxy. However, few studies have focused on the behavior of Se isotopes during oxidative weathering. In this paper, a comprehensive set of Se isotopic composition and concentration data were collected from the weathering profiles of Se-rich shales of the Permian Maokou Formation in Yutangba and Shadi, China to investigate Se isotopic fractionation and Se enrichment during weathering processes. The δ82/76Se in fresh shales (148±118mg/kg Se, 1SD, n =40) from Shadi and Yutangba drill cores varies from −1.69‰ to 1.74‰ with an average of 0.40±0.71‰ (1SD, n =40), consistent with the range in other Phanerozoic shales, suggesting that Se isotopes are not strongly fractionated during Se sequestration in the primary sedimentary environment. However, the strongly weathered Se-rich shales from Shadi and Yutangba profiles are isotopically lighter with average δ82/76Se values of −1.96±1.08‰ (1SD, n =5) and −1.08±1.83‰ (1SD, n =23), respectively. These data suggest that Se isotopes can be fractionated during oxidation and reduction processes associated with weathering, with heavier isotopes removed preferentially during oxidative weathering of shales. Such a shift, if found to be a global phenomenon, would have implications for models of the global Se cycle and interpretation of Se isotope data from past biogeochemical regimes. Locally altered shales exposed in a quarry at Yutangba are extremely enriched in Se with 1642±1505mg/kg (1SD, n =45), approximately 10 times greater than that in unaltered drill core samples. These rocks display very strong variation in δ82/76Se over short distances, with a single 60cm transect showing the most strongly negative and positive δ82/76Se values (−14.20‰ to +11.37‰) observed to date in natural samples. This suggests that Se has undergone multiple cycles of oxidation, mobilization, and re-reduction, resulting in a Se-rich redox front that has migrated downward through the organic-rich shales over time. δ82/76Se values vary sharply over distances as small as 10cm, indicating that Se redox conditions change strongly with position and are controlled by fractures and rock layering. Our data and a simple conceptual model suggest that zones of increased permeability that are accessed first by infiltrating waters are isotopically light, whereas less accessible zones are heavy. Repeated redox cycling accentuates this pattern. Furthermore, the average δ82/76Se in Se-rich shales at the Yutangba weathering system is 0.45±5.77‰ (1SD, n =39), identical with that (0.40±0.71‰) in fresh shales from same locality, implying that Se released by weathering accumulates in the redox front with little loss. The strong Se isotopic fractionation occurring in the redox front implies that Se isotopes can be extensively used in tracing geochemical processes of Se in groundwater system, especially related to fractures. [ABSTRACT FROM AUTHOR]

Abstract: In order to automatically identify fatty acids in plant seed oils, a method was developed to search all saturated fatty acid methyl esters in the sample, subsequently calculate the ECL value of each fatty acid, and finally identify the molecular structure for each component by comparing the ECL of the interest and that in the customised database. Our method was applied to analyse the fatty acid composition of Eucommia ulmoides seed oil. The results show that major polyunsaturated fatty acids are α-linolenic acid (56.5093% of total fatty acids, TFAs) and linolelaidic acid (12.6563% of TFAs). Meanwhile, the main monounsaturated fatty acid is oleic acid whose percentage in the TFAs is 15.8008. Palmitic acid and steartic acid are the dominant saturated fatty acids representing 9.8165% and 2.5942% of TFAs, respectively. The UFA/SFA ratio (6.57) is higher than the recommended value (3) by nutritionists. [Copyright &y& Elsevier]

Abstract: Three new phenothiazine-corrole dyads were prepared by the reaction of phenothiazine-10-carbonyl chloride and mono-hydroxyl triaryl corrole in the presence of DBU. As compared to corrole monomer, these phenothiazine-corrole dyads exhibit significant enhanced DNA photocleavage activity as compared to corrole monomer precursors. [Copyright &y& Elsevier]

Background: Economic reforms in China were implemented approximately 30 years ago. Since then, people's nutrition, living conditions and overall health have continually improved, but there has been an imbalance between the progresses in urban vs rural areas. Height and body mass index (BMI) are regarded as two important indicators of nutritional status and overall health. Aim: The aim of this study was to investigate differences in height and BMI between Chinese youths of rural vs urban areas and further, to determine whether these differences have changed over time (1990s vs 2000s). Subject and methods: 24 194 urban youths and 7130 rural youths were recruited in Hunan province of China. In each gender group, the subjects were divided into eight subsets according to age, geographic area residence, and decade when the youths were measured. Independent t-tests were used to test the differences of height and BMI between the studied groups. Results: Both male and female youths from urban areas were significantly taller than youths from rural areas in both the 1990s and 2000s (all p<0.001), with the exception of the 1990s female 15–18 years subset ( p=0.21). The height of youths was significantly greater in the 2000s compared to the corresponding gender and geographic subset in the 1990s ( p<0.001), except for the female 15–18 years subset from rural areas ( p=0.10). Similar results were obtained for BMI. Conclusion: There are significant differences in height and BMI between youths raised in urban vs rural areas, and positive growth trends of height and BMI over time (1990s vs 2000s) in youths in Hunan Province of China. [ABSTRACT FROM AUTHOR]

Using fully relativistic multiconfiguration Dirac–Fock (MCDF) wavefunctions in an active space approximation, we perform systematic calculations of the energies, wavelengths, and lifetimes for the lowest 143 levels belonging to the 3 p 6 3 d 6 and 3 p 5 3 d 7 configurations of Cr-like ions between Hf XLIX and Au LVI. Additionally, line strengths, oscillator strengths, and radiative rates for the electric dipole (E1), electric quadrupole (E2), magnetic dipole (M1), and magnetic quadrupole (M2) transitions among these levels are reported. In the calculations, the contributions from Breit interaction (BI) and quantum electrodynamics (QED) corrections to the wave functions are taken into account (the addition of the BI and QED in CI affects both the wave functions and the level energies). For some excited states, there are no other theoretical and/or experimental data to compare with to illustrate the quality of our results/assess the accuracy. A similar calculation has been performed with the Flexible Atomic Code (FAC), using W LI as an example. The results obtained in this work are compared with the data compiled in the Atomic Spectra Database (ASD) of the National Institute of Standards and Technology (NIST) and other available theoretical/experimental information. Satisfactory agreement is found between them. The energies agree within 0.8% with the experimental results, and the M1 transition rates agree within 5% with other theoretical results. The present results are more extensive than those from previous calculations and considerably expand the existing data sets for Cr-like ions. This study should be beneficial for the analysis of experimental spectra and modeling of fusion plasmas. [ABSTRACT FROM AUTHOR]