Search

The main chemical component of high-silicon iron tailings (HSITs) is SiO

The eastern part of the North China Craton suffered significant lithospheric thinning since the Mesozoic, and petrogenesis of the Dagushan adakitic diorite porphyries provides an excellent opportunity to investigate the lithospheric thinning mechanism and geodynamic setting. The zircon LA-ICP-MS U–Pb geochronology reveals that the representative Dagushan adakitic porphyry was formed at 120.5 ± 0.5 Ma. The Dagushan diorite porphyries are characterized by the relatively high contents of SiO2 (64.25–65.70 wt%), Al2O3 (15.00–15.38 wt%), Sr (333–491 ppm), low contents of Y (6.50–10.3 ppm), and Yb (0.57–0.85 ppm), and resultant high Sr/Y (47–57) and La/Yb (37–55) ratios, exhibiting geochemical characteristics of typical adakites. Moreover, the relatively high MgO contents (MgO = 2.23–2.29 wt%) and Mg numbers (Mg# = 54–56) of the Dagushan adakitic rocks imply that the pristine adakitic magma interacted with mantle peridotite. However, the zircon Hf isotopic signatures (eHf(t) = − 19.0 to − 28.0; TDM2 = 2378–2944 Ma) suggest an ancient lower crustal source. Therefore, it is proposed that the Dagushan adakitic rock was probably generated by partial melting of delaminated lower crust which was triggered by the Tan-Lu Fault Zone, and the interaction of pristine adakitic magma with mantle peridotite during the ascent finally generated the Dagushan high Mg# adakitic rocks. It is suggested that delamination was an important mechanism for lithospheric thinning of the NCC.

Using low-protein natural rubber latex(LPNRL) as the matrix , hexagonal boron nitride(h-BN) as the thermally conductive filler, and adding γ-polyglutamic acid (γ-PGA), the γ-PGA/h-BN/LPNRL composite films were prepared by mechanical blending. The results showed that γ-PGA could improve the dispersion of h-BN in water and LPNRL matrix. When the mass fraction of γ-PGA and h-BN were 1.5% and 15.0%, the thermal conductivity of the γ-PGA/h-BN/LPNRL composite films increased to 0.634 W/(mK), which was 4.77 times greater than that of pure LPNRL film. The tensile strength of the composite films increased to 8.06 MPa, which was 3.1 times stronger than that of the pure LPNRL films, and the elongation at break was reduced to 980%. The addition of h-BN could significantly improve the thermal stability and tensile strength of the composite films.

Alginate lyases play a vital role in the degradation of alginate, an important marine carbon source. Alginate is a complex macromolecular substrate, and the synergy of alginate lyases is important for the alginate utilization by microbes and the application of alginate lyases in biotechnology. Although many studies have focused on the synergy between different alginate lyases, the synergy between two alginate lyase domains of one alginate lyase has not been reported. Here, we report the synergism between the two catalytic domains of a novel alginate lyase, AlyC6’, from the marine alginate-degrading bacterium Vibrio sp. NC2. AlyC6’ contains two PL7 catalytic domains (CD1 and CD2) that have no sequence similarity. While both CD1 and CD2 are endo-lyases with the highest activity at 30°C, pH 8.0, and 1.0 M NaCl, they also displayed some different properties. CD1 was PM-specific, but CD2 was PG-specific. Compared with CD2, CD1 had higher catalytic efficiency, but lower substrate affinity. In addition, CD1 had a smaller minimal substrate than CD2, and the products from CD2 could be further degraded by CD1. These distinctions between the two domains enable them to synergize intramolecularly in alginate degradation, resulting in efficient and complete degradation of various alginate substrates. The bioinformatics analysis revealed that diverse alginate lyases have multiple catalytic domains, which are widespread, especially abundant in Flavobacteriaceae and Alteromonadales, which may secret multimodular alginate lyases for alginate degradation. This study provides new insight into bacterial alginate lyases and alginate degradation and is helpful for designing multimodular enzymes for efficient alginate depolymerization. IMPORTANCE Alginate is a major component in the cell walls of brown algae. Alginate degradation is carried out by alginate lyases. Until now, while most characterized alginate lyases contain one single catalytic domain, only a few have been shown to contain two catalytic domains. Furthermore, the synergy of alginate lyases has attracted increasing attention since it plays important roles in microbial alginate utilization and biotechnological applications. Although many studies have focused on the synergy between different alginate lyases, the synergy between two catalytic domains of one alginate lyase has not been reported. Here, a novel alginate lyase, AlyC6’, with two functional alginate lyase domains was biochemically characterized. Moreover, the synergism between the two domains of AlyC6’ was revealed. Additionally, the distribution of the alginate lyases with multiple alginate lyase domains was investigated based on the bioinformatics analysis. This study provides new insight into bacterial alginate lyases and alginate degradation.

Schiff base ligands with multiple chelating coordination sites are usually able to quickly capture lanthanide metal ions to form complexes, and it is difficult to twist and construct helical chains. In this work, we used 2-hydroxy-1-naphthaldehyde, propylenediamine, and Ln(NO3)3·6H2O to react at 80 °C in solvothermal to obtain chains [Ln = Dy (1); Ln = Gd (2)] with a helical structure. It is worth noting that 2-hydroxy-1-naphthaldehyde and propylenediamine undergo an in situ reaction under one-pot conditions to form ligand 1,1′-((1E,1′E)-(propane-1,3-diylbis(azaneylylidene))bis(methaneylylidene))bis(naphthalen-2-ol) (H2L). The ligand (L)2− bridges the two metal center Ln(III) ions with a monodentate, causing it to twist into an “S” shape and further form a helical chain. In addition, the independent unit of the helical chain is a single core, and its metal center is in the O9 coordination environment provided by the ligand and the end group coordination NO3− ions. What’s more noteworthy is that chain 1 exhibits single-molecule magnet (SMM) behavior, and its SMM performance is significantly improved under the DC field induction condition of 600 Oe. By Debye model fitting, the effective energy barrier of 1 is 17.8 K, and the relaxation time is 2.4 × 10–6 s. The magnetocaloric effect test of chain 2 is further carried out. When ΔH = 7 T and T = 2 K, its − ΔSm reaches the maximum value of 16.19 J K−1 kg−1.

Recently, hydroxylamine (HAm) was introduced to drive advanced oxidation processes (AOPs) for removing organic contaminants. However, we found that HAm-driven Cu(II)/peroxymonosulfate oxidation of phenol produced p-nitrosophenol, 2-nitrophenol and 4-nitrophenol. The total nitro(so) products accounted for approximately 25.0 % of the phenol transformation at certain condition. SO

Alginate lyases play important roles in alginate degradation in the ocean. Although a large number of alginate lyases have been characterized, little is yet known about those in extremely cold polar environments, which may have unique mechanisms for environmental adaptation and for alginate degradation. Here, we report the characterization of a novel PL7 alginate lyase AlyC3 from Psychromonas sp. C-3 isolated from the Arctic brown alga Laminaria, including its phylogenetic classification, catalytic properties, and structure. We propose the establishment of a new PM-specific subfamily of PL7 (subfamily 6) represented by AlyC3 based on phylogenetic analysis and enzymatic properties. Structural and biochemical analyses showed that AlyC3 is a dimer, representing the first dimeric endo-alginate lyase structure. AlyC3 is activated by NaCl and adopts a novel salt-activated mechanism; that is, salinity adjusts the enzymatic activity by affecting its aggregation states. We further solved the structure of an inactive mutant H127A/Y244A in complex with a dimannuronate molecule and proposed the catalytic process of AlyC3 based on structural and biochemical analyses. We show that Arg(82) and Tyr(190) at the two ends of the catalytic canyon help the positioning of the repeated units of the substrate and that His(127), Tyr(244), Arg(78), and Gln(125) mediate the catalytic reaction. Our study uncovers, for the first time, the amino acid residues for alginate positioning in an alginate lyase and demonstrates that such residues involved in alginate positioning are conserved in other alginate lyases. This study provides a better understanding of the mechanisms of alginate degradation by alginate lyases.

The kinetic data of cyclopentadiene C5H6 oxidation reactions are significant for the construction of aromatics oxidation mechanism because cyclopentadiene C5H6 has been proved to be an important intermediate in the aromatics combustion. Kinetics for the elementary reactions on the potential energy surface (PES) relevant for the C5H6 + HO2 reaction are studied in this work. Stationary points on the PES are calculated by employing the CCSD(T)/cc-pVTZ//B3LYP/6-311G(d,p) level of theory. High-pressure limit and pressure-dependent rate constants for elementary reactions on this PES are calculated using conventional transition state theory (TST), variational transition-state theory (VTST) and Rice-Ramsberger-Kassel-Marcus/master equation (RRKM/ME) theory. In this work, the reaction channels for the C5H6 + HO2 reaction, which include H-abstraction channels from C5H6 by HO2 to form the C5H5 + H2O2 and the addition channels through well-skipping pathways to form the bimolecular products C5H7 + O2 or C5H6O + OH, or through C5H7O2 stabilization and its unimolecular decomposition to form the bimolecular products C5H7 + O2 or C5H6O + OH, namely sequential pathways, are studied. Also, the consuming reaction channels for the compounds C5H6O and C5H7 in the addition products are studied. The dominant reaction channels for these reactions are unraveled through comparing the energy barriers and rate constants of all elementary reactions and it is found: (1) HO2 addition to cyclopentadiene C5H6 is more important than direct H-abstraction. (2) in the HO2 addition channels, the well-skipping pathways and sequential pathways are competing and the well-skipping pathways will be favor in the higher pressures and the sequential pathways will be favor in the higher temperature. (3) The major consumption reaction channel for the five-member-ring compound C5H6O is the reaction channel to form C4H6 + CO and the major consumption reaction channel for the five-member-ring compound C5H7 is the reaction channel to form C3H5 + C2H2. High-pressure limit rate constants and pressure-dependent rate constants for elementary reactions on the PES are calculated, which will be useful in modeling the oxidation of aromatic compounds at low- and medium-temperatures.

Many of the radical–molecule reactions are nonelementary reactions with negative activation energies, which usually proceed through two steps. They exist extensively in the atmospheric chemistry and hydrocarbon fuel combustion, so they are extensively studied both theoretically and experimentally. At the same time, various models, such as a two transition state model, a steady-state model, an equilibrium-state model, and a direct elementary dynamics model are proposed to get the kinetic parameters for the overall reaction. In this paper, a conversion temperature TC1 is defined as the temperature at which the standard molar Gibbs free energy change of the formation of the reaction complex is equal to zero, and it is found that when T ≫ TC1, the direct elementary dynamics model with an inclusion of the tunneling correction of the second step reaction is applicable to calculate the overall reaction rate constants for this kind of reaction system. The reaction class of hydroxyl radical addition to alkenes is chosen as the objects of this study, five reactions are chosen as the representative for the reaction class, and their single-point energies are calculated using the method of CCSD(T)/CBS, and it is shown that the highest conversion temperature for the five reactions is 139.89 K, far below the usual initial low-temperature (550 K) oxidation chemistry of hydrocarbon fuels; therefore, the steady-state approximation method is applicable. All geometry optimizations are performed at the BH&HLYP/6-311+G(d,p) level, and the result shows that the geometric parameters in the reaction centers are conserved; hence, the isodesmic reaction method is applicable to this reaction class. To validate the accuracy of this scheme, a comparison of electronic energy difference at the BH&HLYP/6-311+G(d,p) level and the corrected electronic energy difference with the electronic energy difference at the CCSD(T)/CBS level is performed for the five representative reactions, and it is shown that the maximum absolute deviation of electronic energy difference can be reduced from 2.54 kcal·mol–1 before correction to 0.58 kcal·mol–1 after correction, indicating that the isodesmic reaction method is applicable for the accurate calculation of the kinetic parameters for large-size molecular systems with a negative activation energy reaction. The overall rate constants for 44 reactions of the reaction class of hydroxyl radical addition to alkenes are calculated using the transition-state theory in combination with the isodesmic correction scheme, and high-pressure limit rate rules for the reaction class are developed. In addition, the thermodynamic parameter is calculated and the results indicate that our dynamics model is applicable for our studied reaction class. A chemical kinetic modeling and sensitivity analysis using the calculated kinetic data is performed for the combustion of ethene, and the results indicate the studied reaction is important for the low-to-medium temperature combustion modeling of ethene.

Based on comprehensive analysis of tectonic and fault evolution, core, well logging, seismic, drilling, and production data, the reservoir space characteristic, distribution, origin of fault-karst carbonate reservoir in Yueman block of South Tahe area, Halahatang oilfield, Tarim Basin, were studied systematically. And the regular pattern of hydrocarbon accumulation and enrichment was analyzed systematically based on development practice of the reservoirs. The results show that fault-karst carbonate reservoirs are distributed in the form of “body by body” discontinuously, heterogeneously and irregularly, which are controlled by the development of faults. Three formation models of fault-karst carbonate reservoirs, namely, the models controlled by the main deep-large fault, the secondary fault and the secondary internal fault, are built. The hydrocarbon accumulation and enrichment of fault-karst carbonate reservoirs is controlled by the spatiotemporal matching relation between hydrocarbon generation period and fault activity, and the size and segmentation of fault. The study results can effectively guide the well deployment and help the efficient development of fault-karst carbonate reservoirs of South Tahe area, Halahatang oilfield. Key words: Tarim Basin, Halahatang oilfield, South Tahe area, Ordovician, fault-karst, carbonate reservoir, hydrocarbon accumulation, oil-gas enrichment

We present total-intensity and polarized-intensity images of the Cygnus Loop supernova remnant (SNR) observed by the Five-hundred-meter Aperture Spherical radio Telescope (FAST). The high angular-resolution and high-sensitivity images enable us to thoroughly compare the properties of the northern part with the southern part of the SNR. The central filament in the northern part and the southern part have a similar foreground rotation measure, meaning their distances are likely similar. The polarization analysis indicates that the random magnetic field is larger than the regular field in the northern part, but negligible in the southern part. The total-intensity image is decomposed into components of various angular scales, and the brightness-temperature spectral index of the shell structures in the northern part is similar to that in the southern part in the component images. All these evidence suggest that the northern and southern part of the Cygnus Loop are situated and thus evolved in different environments of interstellar medium, while belonging to the same SNR., Comment: 13 pages, 7 figures, accepted for publication at RAA

Cynanchum auriculatum Royle ex Wight. (CA), Cynanchum bungei Decne. (CB) and Cynanchum wilfordii (Maxim.) Hemsl. (CW) are three close species belonging to the Asclepiadaceous family, and their dry roots as the bioactive part have been revealed to exhibit anti-tumor, neuroprotection, organ protection, reducing liver lipid and blood lipid, immunomodulatory, anti-inflammatory, and other activities. Until 2021, phytochemistry investigations have uncovered 232 compounds isolated from three species, which could be classified into C21-steroids, acetophenones, terpenoids, and alkaloids. In this review, the morphology characteristics, species identification, and the relationship of botany, extraction, and the separation of chemical constituents, along with the molecular mechanism and pharmacokinetics of bioactive constituents of three species, are summarized for the first time, and their phytochemistry, pharmacology, and clinical safety are also updated. Moreover, the direction and limitation of current research on three species is also discussed.

Long noncoding RNA CRNDE (CRNDE) recently emerged as a carcinogenic promoter in various cancers including medulloblastoma. However, the functions and molecular mechanisms of CRNDE to the acquired drug resistance of medulloblastoma are still unclear. The transcript levels of CRNDE were examined in four medulloblastoma cell lines exposed to cisplatin treatment, and IC50 values were calculated. Effects of CRNDE knockdown or miR-29c-3p overexpression on cell viability, colony formation, apoptosis, migration, and invasion were assessed using the CCK-8, colony formation assay, flow cytometry, and Transwell assays, respectively. RNA pulldown and RNA-binding protein immunoprecipitation (RIP) were performed to confirm the molecular interactions between CRNDE and miR-29c-3p involved in medulloblastoma cells. The in vivo role of CRNDE knockdown or miR-29c-3p overexpression on tumor growth and apoptosis was evaluated in a xenograft mouse model of human medulloblastoma. The transcript levels of lncRNA CRNDE were significantly higher in cisplatin-treated tumor cells with higher IC50 values. Depletion of CRNDE inhibited tumor cell proliferation and colony formation, induced cell apoptosis, and suppressed migration and invasion in medulloblastoma cells. Moreover, overexpression of miR-29c-3p inhibited tumor cell proliferation and colony formation, migration, and invasion, and enhanced apoptosis and chemosensitivity to cisplatin. In addition, CRNDE was found to act as a miR-29c-3p sponge. Furthermore, in vivo experiments showed the CRNDE/miR-29c-3p interactions involved in medulloblastoma. Our study demonstrates that CRNDE acts as a critical mediator of proliferation, apoptosis, migration, invasion, and resistance to chemotherapeutics via binding to and negatively regulating miR-29c-3p in medulloblastoma cells. These results provide novel molecular targets for treatment of medulloblastoma.

The intramolecular H-shift reactions of hydroperoxy-alkenyl-peroxy radicals are one of the key reaction classes in low-temperature combustion for alkenes. Depending on the types of carbons from whi...

In this paper, effects of anisotropic thermal conductivity and the Lorentz force in a ferro-nanofluid induced by external magnetic fields are investigated. The nanofluid is modeled as a non-linear single-phase fluid, where the viscosity is considered to depend on the nanoparticle concentration; the thermal conductivity shows anisotropy due to the existence of the magnetic field. The anisotropic thermal conductivity tensor, which depends on the magnetic field vector, is derived by considering the principle of material frame indifference of Continuum Mechanics. Numerical simulations are performed in a horizontal annulus enclosure. Effects of the nanoparticle concentration, magnetic distribution, and the dimensionless parameters, such as the Rayleigh number and the Hartmann number, are studied. The numerical results indicate that due to the anisotropic thermal conductivity, the isotherms become elliptic and deviate significantly from a circle which is a typical distribution with isotropic thermal conductivity; furthermore the elliptic shape changes as the direction of the magnetic field varies while the heat transfer is always much faster in the direction parallel to the magnetic field. For the range of the dimensionless parameters studied here, the Nusselt number increases significantly as the Rayleigh number (ranging from 2500 to 50,000) increases; depending on the situation, the magnetic field (the Hartmann number which ranges from 0 to 1) may enhance or diminish the thermal performance. In addition, the streamlines are more organized and less wavy when there exists a magnetic field; this could be attributed to the suppressive effect of the Lorentz force.

Ulvan is an important marine polysaccharide. Bacterial ulvan lyases play important roles in ulvan degradation and marine carbon cycling. Until now, only a small number of ulvan lyases have been characterized. Here, a new ulvan lyase, Uly1, belonging to polysaccharide lyase family 24 (PL24) from the marine bacterium Catenovulum maritimum, is characterized. The optimal temperature and pH for Uly1 to degrade ulvan are 40°C and pH 9.0, respectively. Uly1 degrades ulvan polysaccharides in the endolytic manner, mainly producing ΔRha3S, consisting of an unsaturated 4-deoxy-l-threo-hex-4-enopyranosiduronic acid and a 3-O-sulfated α-l-rhamnose. The structure of Uly1 was resolved at a 2.10-Å resolution. Uly1 adopts a seven-bladed β-propeller architecture. Structural and site-directed mutagenesis analyses indicate that four highly conserved residues, H128, H149, Y223, and R239, are essential for catalysis. H128 functions as both the catalytic acid and base, H149 and R239 function as the neutralizers, and Y223 plays a supporting role in catalysis. Structural comparison and sequence alignment suggest that Uly1 and many other PL24 enzymes may directly bind the substrate near the catalytic residues for catalysis, different from the PL24 ulvan lyase LOR_107, which adopts a two-stage substrate binding process. This study provides new insights into ulvan lyases and ulvan degradation. IMPORTANCE Ulvan is a major cell wall component of green algae of the genus Ulva. Many marine heterotrophic bacteria can produce extracellular ulvan lyases to degrade ulvan for a carbon nutrient. In addition, ulvan has a range of physiological bioactivities based on its specific chemical structure. Ulvan lyase thus plays an important role in marine carbon cycling and has great potential in biotechnological applications. However, only a small number of ulvan lyases have been characterized over the past 10 years. Here, based on biochemical and structural analyses, a new ulvan lyase of polysaccharide lyase family 24 is characterized, and its substrate recognition and catalytic mechanisms are revealed. Moreover, a new substrate binding process adopted by PL24 ulvan lyases is proposed. This study offers a better understanding of bacterial ulvan lyases and is helpful for studying the application potentials of ulvan lyases.

Preoperative anxiety is common and often comes with a higher probability of worse recovery. However, the neurological mechanism of the effect of preoperative anxiety on general anesthesia and subsequent awakening remains unknown. In this study, we report an anxious state results in delayed awakening in anxiety model mice from sevoflurane general anesthesia. More profound inhibition of DA neurons in the VTA contributes to delayed awakening. Optogenetic stimulation of VTA DA neurons can reverse the delay. The results indicate that VTA DA neurons may be involved in the delay in awakening from general anesthesia caused by anxiety.

Background: Hepatic fibrosis is an inflammatory liver disease, and there is no effective therapy at present. Astilbin is a bioactive ingredient found in many medicinal and food plants, with antioxidative, anti-inflammatory, and antitumor properties. Objectives: This study aimed to investigate the protective effect and related molecular mechanism of astilbin against carbon tetrachloride (CCl4)-induced liver fibrosis in rats. Methods: Liver fibrosis was induced by injection of CCl4 in male Sprague-Dawley rats, and those rats were then treated with astilbin at different concentrations. Pathological changes, collagen production, inflammatory cytokine, and oxidative stress were evaluated to evaluate the effects of astilbin on CCl4-induced hepatic fibrosis. Real-time PCR and western blot were performed to detect the mRNA and protein expression of indicated genes. Results: We discovered that CCl4 caused significant fibrosis damage in rat liver, and astilbin dose-dependently improved the liver functions and fibrosis degree. Astilbin treatment significantly decreased collagen production, inflammatory response, and oxidative stress in vivo. Mechanically, administration of astilbin obviously elevated the hepatic levels of Nrf2 and its downstream components, including NAD(P)H:quinone oxidoreductase 1 (Nqo1), heme oxygenase (HO-1), glutamate-cysteine ligase catalytic subunit, and glutamate cysteine ligase modifier. Conclusions: Taken together, these findings demonstrate that astilbin could protect against CCL4 induced-liver fibrosis in rats.

The reactions of cycloaddition, intramolecular H-shift and concerted elimination of alkenyl peroxy radicals are three kinds of important reactions in the low temperature combustion of alkenes. In this study, the cycloaddition reactions are divided into classes considering endo-cycloaddition, exo-cycloaddition and the size of the transition states; the intramolecular H-shift reactions are divided into classes depending upon the ring size of the transition states and the type of C–H bonds from which the hydrogen atom is transferred; the concerted elimination reactions are divided into classes according to the type of H–CβCαOO bond that is broken. All geometry optimizations are performed at the B3LYP/6-31G(2df,p) level. With the electronic structure calculations being performed using the composite Gaussian-4 (G4) method, high pressure limit rate constants and pressure-dependent rate constants at pressures varying from 0.01 to 100 atm are calculated by using canonical transition state theory and the Rice–Ramsberger–Kassel–Marcus/master equation method, respectively. All rate constants are given in the form of the modified Arrhenius expression. The high pressure limit rate rules and the pressure-dependent rate rules are derived by averaging the rate constants of a representative set of reactions in each class. The results show that the rate rules for these three classes of reactions have a large uncertainty and the impact of the pressure on the rate constants increases as temperature increases.

This paper examines choice behaviors pertaining to the time at which users of plug-in hybrid electric vehicle with 24 km electric range charge their vehicles after arriving at home under a dynamic electricity pricing scheme. The following mutually exclusive alternatives are presented: no charging, charging immediately after arriving at home, charging at the cheapest time, and charging at other times. Four versions of a mixed logit model with unobserved heterogeneity are applied to panel data on vehicle usage from 9 households with 2226 observations in Toyota City. Estimation results suggest that users’ willingness to charge become stronger with increasing driving distance when the driving distance is less than the electric range of 24 km, while tend not to charge when the driving distance is longer than the electric range. Users who return home at the cheapest time or during the day are willing to charge immediately after arriving at home. Electricity prices significantly affect choices to charge at the cheapest time for all users, and stay-at-home mother users and users returning home in the evening tend to charge at the cheapest time. Users returning home in the evening also tend to charge at other times, and being accustomed to charge at a certain time increases the probability of charging at other times. In addition, considerable variations are found across individuals with respect to their preferences for charge timing alternatives as well as for electricity prices.

The relativistic electrons rotate in the enhanced magnetic field of the supernova remnants and emit the synchrotron radio emission. We aim to use the Five-hundred-meter Aperture Spherical radio Telescope (FAST) to obtain a sensitive continuum map of the supernova remnant VRO 42.05.01 (G166.0+4.3) at 1240 MHz. The 500 MHz bandwidth is divided into low and high-frequency bands centered at 1085 and 1383 MHz to investigate the spectral index variations within the remnant, together with the Effelsberg 2695 MHz data. We obtained an integrated flux density of 6.2 ± 0.4 Jy at 1240 MHz for VRO 42.05.01, consistent with previous results. The spectral index found from temperature-temperature plot (TT-plot) between 1240 and 2695 MHz agrees with previous values from 408 MHz up to 5 GHz. The three-band spectral index distribution shows a clear flatter value of α ∼ −0.33 in the shell region and steeper index of α = −0.36 to −0.54 in the wing region. The flatter spectral index in the shell region could be attributed to a second-order Fermi process in the turbulent medium in the vicinity of the shock and/or a higher compression ratio of shock and a high post-shock density than that in elsewhere.

Randomized block coordinate descent type methods have been demonstrated to be efficient for solving large-scale optimization problems. Linear convergence to the unique solution is established if the objective function is strongly convex. In this paper we propose a randomized block coordinate descent algorithm for solving the matrix least squares problem min X ∈ R m × n ‖ C − AXB ‖ F with A ∈ R p × m , B ∈ R n × q , and C ∈ R p × q . We prove that the proposed algorithm converges linearly to the unique minimum norm least squares solution (i.e., A † C B † ) without the strong convexity assumption. Instead, we only need that B has full row rank. Numerical experiments are given to illustrate the theoretical results.

We report on the continuum and polarization observations of the Cygnus Loop supernova remnant (SNR) conducted by the Five-hundred-meter Aperture Spherical radio Telescope (FAST). FAST observations provide high angular resolution and high sensitivity images of the SNR, which will help to disentangle its nature. We obtained Stokes I, Q and U maps over the frequency range of 1.03 – 1.46 GHz split into channels of 7.63 kHz. The original angular resolution is in the range of ∼ 3 ′ − ∼ 3 ′ .8 , and we combined all the data at a common resolution of 4 ′ . The temperature scale of the total intensity and the spectral index from the in-band temperature-temperature plot are consistent with previous observations, which validates the data calibration and map-making procedures. The rms sensitivity for the band-averaged total-intensity map is about 20 mK in brightness temperature, which is at the level of confusion limit. For the first time, we apply rotation measure (RM) synthesis to the Cygnus Loop to obtain the polarization intensity and RM maps. The rms sensitivity for polarization is about 5 mK, far below the total-intensity confusion limit. We also obtained RMs of eight extragalactic sources, and demonstrate that the wide-band frequency coverage helps to overcome the ambiguity of RM determinations.

Diabetic cardiomyopathy (DCM) is one of the chief diabetes mellitus complications. Inflammation factors may be one reason for the damage from DM. The purpose of this research is to study the potential protective effects of puerarin on DM and the possible mechanisms of action related to NF-κB signal pathway. Following administration of puerarin to the disease model rat, several changes were observed including the changes of serum biochemical index, improved diastolic dysfunction, and enhanced endogenous antioxidant enzymes activities, further NF-κB signaling activation. Puerarin showed cardio-protective effects on DCM by inhibiting inflammation, and it might be a potential candidate for the treatment of DCM.

Because of the large-size caves and fractures, carbonate reservoirs are heterogeneous. Based on the characteristics of fractured-cavernous reservoir, seismic and geology data, an interpretation model for well test of natured vuggy reservoir was developed in consideration of the existence of large-scale cave near the wellbore. The equations for expressing the pressure at bottom hole were obtained by using the concept of Green’s function and the Laplace transformation technique. The analysis on the affecting factors of dynamic pressure at well bottom indicates that with the existence of discontinuous cavity-region in the formation, the pressure derivative curve will concave downward which is caused by physical property differences between inside and outside the cavity. The size of cavity mainly affects the amplitude of the pressure derivative reduction. The results of a real testing case interpretation have good consistency with geological features, which proved the mathematical model.

Objectives This study is designed to investigate the effects and mechanisms of sinomenine (Sin) in stress load-induced heart failure in mice. Methods We used aortic constriction (AB) to cause pressure overload as our heart failure model. Sin was received in mice as the treatment group. Cardiac function and structural changes were detected using echocardiography. Heart–lung mass ratios were measured. The serum levels of IL-10 and IL-17 proteins were detected by using ELISA, cardiac hypertrophy markers atrial natriuretic peptide (ANP), myocardial I and III collagen mRNA levels were detected by RT-PCR. Myocardial type I and III collagen protein levels were detected by Western blotting. Key findings Sin significantly improved stress load-induced heart failure (P < 0.05), reduced the heart–lung mass ratio, ANP, collagen-I and -III mRNA and protein levels (P < 0.05); Sin can enhance the ratio of IL-10/IL-17. Conclusion Sin may be a promising drug target to improve heart failure. Its role is related to reduce serum ANP levels, inhibit the mRNA and protein level of type I and III collagen and enhance the ratio of IL-10/IL-17.

This study explores how battery electric vehicle users choose where to fast-charge their vehicles from a set of charging stations, as well as the distance by which they are generally willing to detour for fast-charging. The focus is on fast-charging events during trips that include just one fast-charge between origin and destination in Kanagawa Prefecture, Japan. Mixed logit models with and without a threshold effect for detour distance are applied to panel data extracted from a two-year field trial on battery electric vehicle usage in Japan. Findings from the mixed logit model with threshold show that private users are generally willing to detour up to about 1750 m on working days and 750 m on non-working days, while the distance is 500 m for commercial users on both working and non-working days. Users in general prefer to charge at stations requiring a shorter detour and use chargers located at gas stations, and are significantly affected by the remaining charge. Commercial users prefer to charge at stations encountered earlier along their paths, while only private users traveling on working days show such preference and they turn to prefer the stations encountered later when choosing a station in peak hours. Only private users traveling on working days show a strong preference for free charging. Commercial users tend to pay for charging at a station within 500 m detour distance. The fast charging station choice behavior is heterogeneous among users. These findings provide a basis for early planning of a public fast charging infrastructure.

AIM: To comparatively analyze the application of laser confocal microscopy and corneal smear in the diagnosis of fungal keratitis. METHODS: Totally 77 patients(77 eyes)diagnosed as fungal keratitis were selected. Laser confocal microscopy and corneal smear examination were performed to observe the characteristics of the images, and the detection rate of fungus were compared between the two methods. RESULTS: Of the 77 patients, 66 eyes(86%)were positive and 11 eyes were negative detected by laser confocal microscopy; 51 eyes(66%)were positive and 26 eyes were negative detected by corneal smear examination, the difference was statistically significant compared between two group(PCONCLUSION: Laser corneal confocal microscopy is relatively safe and sensitive. If combined the application of laser corneal confocal microscopy and corneal smear examination in clinical, the diagnosis rate of fungal keratitis may be improved.

A detailed combustion mechanism of hydrocarbon fuels usually contains a large number of reactions and need to have kinetic data assigned to them, where the rate constants are usually given by approximate estimation leading to inaccuracies. In this work, a method for construction transition state (TS) and an isodesmic reactions correction scheme for accurate and automatic calculation of rate constants have been designed. These methods are tested using the cyclization reactions of QOOH radicals and the concerted elimination reactions of RO2 radicals. The results show that the automatic TS construction method is effective to construct the initial guesses of the transition states, the isodesmic reactions corrected results are close to the CCSD(T) results and some of the rate constants are significantly different from the rate constants used in the automated mechanism generator, indicating that it is necessary and significant to perform on-the-fly accurate calculation of rate constants in an automated mechanism generator.

The Gongchangling iron deposit located in the northeast of the North China Craton is hosted in late Neoarchean Algoma-type BIFs. It is famous for the major production of high-grade iron ore in the Gongchangling No.2 mining area in China. With regard to the genesis of high-grade iron ore, more and more evidences indicate that it was related with hydrothermal enrichment of BIFs. However, the hydrothermal nature was argued for meteoric, metamorphic or migmatitic fluid. In this study, the trace element compositions of garnet from the altered wall-rock of high-grade iron ore obtained by LA–ICP–MS show compositional zoning, indicating it is a metamorphic origin. These garnets yield a Sm–Nd isochron age of 1888 ± 77 Ma, interpreted as the time of metamorphism in this area. LA–ICP–MS U–Pb dating of zircon from the upper migmatite zone shows that the migmatitic granite was formed at 2478 ± 36 Ma. Since the REE patterns of garnet suggest that it was formed in the nearly neutral fluid rather than the acid meteoric fluid in the Paleoproterozoic. Hence, combined the ages of metamorphism and migmatization with high-grade iron ore of 1840 ± 7 or 1860 ± 7 Ma obtained by previous studies, it indicates that the genesis of the high-grade iron ore derived from the enrichment of BIFs by metamorphic hydrothermal fluid.

To investigate the effects and mechanisms of fasudil (Fas) on cardiac hypertrophy (CH) induced by isoprenaline(Iso) in rats.Except for the normal control group, the rest three groups rats were injected subcutaneously with Iso(5mg/kg) for setting up CH model. SD rats were randomly divided into four groups:Normal control group, Iso model group, Fas with low-dose group (5 mg/kg, i.p) and Fas with high-dose group (20 mg/kg, i.p). Animals were treated with Fas for 8 weeks. After the treatment, the following index were detected:heart rate (HR), left ventricular systolic pressure (LVSP), left ventricular end diastolic pressure (LVEDP), left ventricular systolic maximum rate (+dp/dtCompared with normal control group, HR and LVEDP wereincreased significantly, while LVSP and ±dp/dtmax were decreased significantly; HWI was increased significantly in CH group; The myocardial cell volume and the cell gap were increased,cells arranged disorder, and severe myocardial interstitial fibrosis was presented in CH group. The expression of ERK1/2 mRNA was significantly increased. After Fas treatment, the systolic and diastolic functions of heart were improved, cell volume was reduced, cell gap became small, cells arranged in neat rows, and the fibrosis was significantly reduced. The expressions of RhoA, ERK1/2 mRNA were significantly reduced. The damages of myocardial tissue were improved in different degrees.ERK1/2 signaling pathway is involved in Iso induced CH. Fas protects against the CH of rats induced by Iso, which mechanisms may be related with blocking ERK1/2 signaling pathway.

The isodesmic reaction method is applied to calculate the potential energy surface (PES) along the reaction coordinates and the rate constants of the barrierless reactions for unimolecular dissociation reactions of alkanes to form two alkyl radicals and their reverse recombination reactions. The reaction class is divided into 10 subclasses depending upon the type of carbon atoms in the reaction centers. A correction scheme based on isodesmic reaction theory is proposed to correct the PESs at UB3LYP/6-31+G(d,p) level. To validate the accuracy of this scheme, a comparison of the PESs at B3LYP level and the corrected PESs with the PESs at CASPT2/aug-cc-pVTZ level is performed for 13 representative reactions, and it is found that the deviations of the PESs at B3LYP level are up to 35.18 kcal/mol and are reduced to within 2 kcal/mol after correction, indicating that the PESs for barrierless reactions in a subclass can be calculated meaningfully accurately at a low level of ab initio method using our correction scheme. High-pressure limit rate constants and pressure dependent rate constants of these reactions are calculated based on their corrected PESs and the results show the pressure dependence of the rate constants cannot be ignored, especially at high temperatures. Furthermore, the impact of molecular size on the pressure-dependent rate constants of decomposition reactions of alkanes and their reverse reactions has been studied. The present work provides an effective method to generate meaningfully accurate PESs for large molecular system.

As the rate-determining step in native chemical ligation reactions, the thiol–thioester exchange step is important in determining the efficiency of the ligations of peptides. In the present study, systematic theoretical calculations were carried out on the relationships between the structure of different thioesters and the free energy barriers of the thiol–thioester exchange step. According to the calculation results, the thiol–thioester exchange step is disfavored by the steric hindrance around the carbonyl center, while the electronic effect (i.e. conjugation and hyper-conjugation effects) becomes important when the steric hindrance is insignificant.

The S―S bond cleavage plays an important role in affecting the reactivity or biological activities of disulfide-based compounds. With the aid of density functional theory (DFT) calculations, the present study focuses on predicting the S―S bond dissociation energies (BDEs) of disulfides. The range of BDEs of different types of disulfides was constructed for the first time. It was found that the electronic effect (and especially the conjugation effect) of substituents is predominant in determining the S―S bond strength of disulfides. By contrast, the steric effect is insignificant for most molecules due to the long S―S bond distances. We hope that the present study will benefit the future development of more powerful strategies in activating the S―S bond of disulfides. Copyright © 2015 John Wiley & Sons, Ltd.

To enhance the structural diversity of tanshinones and provide more derivatives for the biological studies, a one-pot combinatorial modification strategy was performed on total tanshinones. Six new quinoxlinetanshinones 1–6 were subsequently isolated from the combinatorial modified semi-synthetic mixture. The structures were elucidated by spectroscopic analysis in combination with single-crystal X-ray diffraction. These quinoxlinetanshinones demonstrated strong DNA binding properties. Rapid synthesis of new quinoxlinetanshinones with significant biological activity highlights the great potential of one-pot combinatorial modification for the diversification of natural products.

Objective Estimate predictive associations of marital status with social dysfunction in schizophrenia patients. Methods 817 schizophrenia patients lived in the community of Dongguan, Guangdong province, China, were investigated with the Social Disability Screening Schedule (SDSS) during a three-month period (1.2010–3.2010). The demographic data were harvested. The χ2 test, t test, and fisher's exact were used for comparisons between groups, as appropriate. Multinomial logistic regression (MLR) was used to analyze the predictive associations of demographic variables to the grading of social dysfunctions. Results The study group consisted of male and female patients aged 16–59 years, 407 females, and 410 males with the mean age (40.7 ± 9.5) years. Analysis of the data revealed significant differences in course of disease and marital status among patients (with and without dysfunction). The married patient made a significant difference with divorced/widowed patient in mildly–moderately social dysfunction. There was a significant difference in married and never-married patient with mildly and profoundly social dysfunction. Significant differences were noticed in the self care and occupational roles of the married patient with that of the never-married. Conclusion This study confirmed that bad marital status is associated with higher odds of social dysfunction among patients with schizophrenia living in the community. These effects should be included in considerations of public health investments in preventing and treating mental disorders.

This paper aims to examine choice behavior in respect of the time at which battery electric vehicle users charge their vehicles. The focus is on normal charging after the last trip of the day, and the alternatives presented are no charging, charging immediately after arrival, nighttime charging, and charging at other times. A mixed logit model with unobserved heterogeneity is applied to panel data extracted from a two-year field trial on battery electric vehicle usage in Japan. Estimation results, obtained using separate models for commercial and private vehicles, suggest that state of charge, interval in days before the next travel day, and vehicle-kilometers to be traveled on the next travel day are the main predictors for whether a user charges the vehicle or not, that the experience of fast charging negatively affects normal charging, and that users tend to charge during the nighttime in the latter half of the trial. On the other hand, the probability of normal charging after the last trip of a working day is increased for commercial vehicles, while is decreased for private vehicles. Commercial vehicles tend not to be charged when they arrival during the nighttime, while private vehicles tend to be charged immediately. Further, the correlations of nighttime charging with charging immediately and charging at other times reveal that it may be possible to encourage charging during off-peak hours to lessen the load on the electricity grid. This finding is supported by the high variance for the alternative of nighttime charging.

As an excellent alternative to native chemical ligations, the ligation–desulfurization strategy enables the ligations on the other N-terminal peptides (in addition to Cys) and is highly promising in peptide synthesis. In the present study, the relative facility of the desulfurization on the pre-sulfurized amino acids and their carboxylate derivatives has been examined with the aid of density functional theory calculations. It is found that the C–SH bond strengths of the sulfurized amino acids directly relate to the stability of the formed radical. By contrast, the carboxylation of the sulfurized amino acids greatly stabilizes the carbonyl radical center, and both the steric and electronic effects are important factors in determining the C–SH bond strength of the carboxylate precursors. Copyright © 2015 John Wiley & Sons, Ltd.

This study aims to explore how factors including charging infrastructure and battery technology associate the way people currently charge their battery electric vehicles, as well as to explore whether good use of battery capacity can be encouraged. Using a stochastic frontier model applied to panel data obtained in a field trial on battery electric vehicle usage in Japan, the remaining charge when mid-trip fast charging begins is treated as a dependent variable. The estimation results obtained using four models, for commercial and private vehicles, respectively, on working and non-working days, show that remaining charge is associated with number of charging stations, familiarity with charging stations, usage of air-conditioning or heater, battery capacity, number of trips, Vehicle Miles of Travel, paid charging. However, the associated factors are not identical for the four models. In general, EVs with high-capacity batteries are initiated at higher remaining charge, and so are the mid-trip fast charging events in the latter period of this trial. The estimation results also show that there are great opportunities to encourage more efficient charging behavior. It appears that the stochastic frontier modeling method is an effective way to model the remaining charge at which fast-charging should be initiated, since it incorporates trip and vehicle characteristics into the estimation process to some extent.

The deflectable nose missile has a longer range by deflecting its nose to improve its aerodynamic feature. Based on detached eddy simulation (DES), the supersonic flow fields of a missile with deflectable nose are simulated numerically and its aerodynamic force coefficients are calculated under the condition of the deflection angles vary from 0° to 8°, angles of attack, 0°–8°, and mach numbers, 2 to 5. Coupling these aerodynamic coefficients with the plumb plane ballistic equations, the extended flight range has been calculated. Furthermore, the genetic algorithm (GA) is employed for the solution of maximum range of the deflected missile.

A series of experimental simulations of the genetic mechanism of banded iron formations has been conducted using a suite of self-designed glassware to model the hypergene circulation of surface water. The simulation process involved two parts: in the first part, the weathering and leaching of basalt by strongly acidic meteoric water during early Precambrian volcanism would have resulted in amorphous silica precipitation and strongly acidic ore-bearing solutions (pH 2 -saturated meteoric water without contamination of other volcanic gases would increase the pH value of the solution. When the pH increased to 1.25–5.50, ferric hydroxides and amorphous silica would alternately precipitate owing to periodic heating and continuous addition of high-pH basalt-leaching solutions. This is a possible explanation of the genetic mechanism of the Algoma-type banded iron formations.

One new stenine-type alkaloid, tuberostemonine D ( 1 ), together with five known stenine-type alkaloids ( 2 – 6 ) and two known stemoninine-type alkaloids ( 7 and 8 ), were isolated from the roots of Stemona tuberosa . Their structures were elucidated by extensive spectroscopic methods (IR, UV, MS, 1D and 2D NMR), and the structure of 1 was further confirmed by X-ray diffraction analysis. First simultaneous isolation of stenine- and stemoninine-type alkaloids not only added a new chemical type and increased the chemical diversity of Stemona tuberosa , but also provided chemotaxonomic clues for the close relationship between genera Stemona and Stichoneuron , and favored retaining them in the same family.

The Gongchangling BIFs are located in the Anshan–Benxi area, northeastern part of the North China Craton, of which the No. 2 mining area is the largest and most typical high-grade iron ore producing area in China. In this study, the mineralogy, petrology and chemistry of iron ores (BIFs and high-grade iron ores) and their wall-rocks (amphibolite and garnet–chlorite schist) from the Gongchangling No. 2 mining area were examined to constrain the genesis of high-grade iron ore. The BIFs are composed essentially of magnetite and quartz, in addition to actinolite in a few samples; while the high-grade iron ores are mainly composed of magnetite and the quartz is relatively rare. The low contents of Al 2 O 3 , TiO 2 and HFSE in the BIFs and high-grade iron ores indicate that they are marine chemical precipitates with little input of terrigenous clastic sediments. The magnetite and quartz from BIFs and high-grade iron ores exhibit the similar chemical composition. The REY patterns of BIFs and high-grade iron ores suggest their precipitation after mixing of hydrothermal component with seawater in certain proportions under relatively low oxygen level, and the obvious positive Eu anomalies indicate that high-temperature hydrothermal fluids which percolate and dissolve the submarine volcanic rock may supply the ore-forming material to the Gongchangling iron deposit. The amphibolite as interlayer of BIFs recorded the metamorphic temperature of 567 ± 25 °C, moreover, the garnet from wall-rock of high-grade iron ore exhibits the growth zoning produced during prograde metamorphism, indicating that metamorphic hydrothermal fluids played an important role in the genesis of high-grade iron ore. It was proposed that the Gongchangling iron deposit was formed in an arc-related tectonic setting at the late Neoarchean, then it underwent lower amphibolite facies metamorphism, and the high-grade iron ore is the reformed product of BIFs by metamorphic hydrothermal fluids.