Wang Hai-Xia

Catastrophic eco-environmental change in the Songnen Plain, northeastern China since 1900s

Although the Songnen Plain in the northeastern China was developed relatively late in the temperate zone of the world, its eco-environment has changed greatly. This paper analyzes the changes of land cover and the rates and trends of desertification during the past 100 years in the Songnen Plain. According to the macroscopic analysis, we find that the eco-environment in the plain has reached to the threshold of catastrophic change since the 1950s. The Thom Needle Catastrophic Model was used to determine and validate this conclusion. Human activities, including large-scale construction projects, such as huge dams and dikes, and excessive grazing were the primary factors contributing to regional eco-environmental catastrophe. And irrational reclamation of the wilderness also affected the eco-environmental change. The results reveal the complex human-land interactions.

Isolation, purification and identification of antioxidants from Lepidium latifolium extracts

Antioxidant potencies of an ethanolic extract and its components from Lepidium latifolium were investigated. In this study, we found that the ethyl acetate soluble fraction of L. latifolium was a rich source of antioxidant, resulting from its high total phenolic content. To determine the antioxidant components of the ethyl acetate fraction, a bioassay-guided fractionation approach using 1,1-diphenyl-2-picrylhydrazyl, 2,2′-azinobis-(3-ethylbenzthiazoline-6-sulfonate), and ferric reducing antioxidant power assays were conducted. Nine compounds were isolated and their structures were identified by MS and NMR spectral data and comparison to reported data. They are Quercetin-3-O-β-d-sophoroside-7-O-α-l-rhamnoside (1), Apetalumoside B6 (2), Kaempferol-3-O-β-d-glucopyranosyl-(1-2)-β-d-glucopyranoside-7-O-β-d-glucopyranoside (3), Kaempferol-7-O-α-l-rhamnopyranoside (4), Kaempferol-3-O-β-d-glucopyranoside-7-O-α-l-rhamnopyranoside (5), Kaempferol-3-O-(2-O-feruloyl-β-d-glucopyranosyl-(1-2)-β-d-glucopyranoside)-7-O-glucopyranoside (6), Kaempferol-3-O-β-d-sophoroside-7-O-α-l-rhamnoside (7), Kaempferol-3-O-robinoside-7-O-(2″″-(E)-feruloyl)-sophoroside (8), Quercetin-3-O-(2,6-di-O-β-d-glucopyranosyl)-β-d-glucopyranoside-7-O-α-l-rhamnopyranoside (9), compounds 1, 2, 4, and 8 had potent free radical scavenging activity. The IC50 values of these compounds were 9.8–12.3 and 7.4–31.4 μg/mL in DPPH and ABTS assays, respectively. The results indicate that L. latifolium is a potential natural source of antioxidants to treat several diseases related to oxidant by-products of human metabolism.

Measured and Simulated Performance of a Four-Segmented Clover Detector

Gamma rays with energies between 80 keV and 1500 keV produced by 133Ba and 152Eu standard sources are measured with the clover detector. Relative efficiencies and add-back factors are determined in both crystals and full clover modes. The add-back characteristics have been calculated using Monte-Carlo simulation code Geant4. The simulation and measurements agree very well.

Properties of the β-Delayed Proton Decay of 147Er

The ?-delayed proton decay of 147Er is studied experimentally using the 68Ni+92 Mo reaction at a beam energy of 383 MeV. Based on a He-jet apparatus coupled with a tape transport system, the ?-delayed proton radioactivities both from the ?s1/2 ground state and the ?h11/2 isomer in 147Er are identified by proton-? coincidence measurements. By analyzing the time distribution of the 4+ ? 2+? transition in the grand-daughter nucleus 146Dy, a half-life of 1.6 ? 0.2 s is determined for the ?h11/2 isomer in 147Er. The half-life for the ground state of 147Er is estimated to be 3.2 ? 1.2 s.

A New High-Spin Level Scheme of 128I

High-spin states in the odd-odd nucleus 128I are investigated via the 124Sn(7Li,3n)128I reaction at 28 and 32 MeV beam energies. A new level scheme of 128I is established up to high-spin states at Iπ = 16, including 48 levels and 72 γ transitions. The present level scheme is largely different from the one in a recent publication due to identification of several doublet and triplet γ transitions and their proper placements in the level scheme. The high-spin level structure exhibits no obvious collective properties and is possibly associated with two and multi-quasiparticle configurations.

Anti-inflammatory activity of compounds isolated from Swertia mussotii

Abstract Six compounds were isolated from an ethanol extract of Swertia mussotii and identified as 2-phenylethyl-β-D-glucoside (1), amaroswerin (2), 1,3,7,8-tetrahydroxyxanthone (3), swertiamarine (4), 1,3,8-trihydroxy-5-methoxyxanthone (5) and methylswertianin (6). Compounds 1, 2 and 6 were isolated from S. mussotii for the first time. The anti-inflammatory activities of the compounds were evaluated by determining their effect on the production of NO by LPS-stimulated RAW264.7 cells. Amaroswerin was the most potent inhibitor of NO release, with an IC50 value of 5.42 μg/mL. Treatment with amaroswerin inhibited expression of iNOS at both protein and mRNA levels. Amaroswerin also dose-dependently suppressed production of TNF-α, IL-6 and IL-1β and reduced expression of mRNA for these LPS-stimulated pro-inflammatory mediators. Amaroswerin thus inhibits the expression of iNOS, TNF-α, IL-6 and IL-1β by downregulating transcription in LPS-induced RAW264.7 macrophage cells, indicating that amaroswerin may be a valuable therapeutic agent for the treatment of inflammatory diseases.

Properties of the ν7/2−[503](f7/2) band in 185Pt

High-spin states in 185Pt have been reinvestigated via the reaction 173Yb(16O, 4n) at a beam energy of 90 MeV. The previously known band based on the ν7/2−[503](f7/2) Nilsson orbital has been extended to higher spin states. Properties of the ν7/2−[503](f7/2) band have been discussed with an emphasis on the evolution of configuration while increasing the spin.

Properties of the β-delayed proton decay of 146Ho

The proton-rich isotope 146Ho was produced via the fusion-evaporation reaction 92Mo (58Ni, 3p1n). The β-delayed proton decay of 146Ho was studied by proton-y coincidence measurements using a He-jet tape transport system. The γ-transitions in 145Tb following the proton emissions were observed, and the β-delayed proton branching ratios to the final states in the grand-daughter nucleus 145Tb were determined. According to the relative branching ratios, the ground-state spin of 146Ho has been proposed and the possible configuration discussed.

Antiproliferative Activity of Phenylpropanoids Isolated from Lagotis brevituba Maxim

The aim of the present study was to evaluate the antiproliferative effect of phenylpropanoids isolated from the n‐BuOH‐soluble fraction of an ethanolic extract of Lagotis brevituba Maxim. The phenylpropanoids were identified as echinacoside, lagotioside, glucopyranosyl(1–6)martynoside, plantamoside, and verbascoside. Three of the compounds, lagotioside, glucopyranosyl(1–6)martynoside, and plantamoside, were isolated from L. brevituba for the first time. The antiproliferative activity of the isolates was evaluated in human gastric carcinoma (MGC‐803), human colorectal carcinoma (HCT116), human hepatocellar carcinoma (HepG2), and human lung cancer (HCT116) cells using an 3‐(4,5‐dimethylthiazol‐2‐yl)‐2,5‐diphenyltetrazolium bromide assay. Plantamoside showed promising activity against MGC‐803 cells, with a half maximal inhibitory concentration value of 37.09 μM. The mechanism of the pro‐apoptosis effect of plantamoside was then evaluated in MGC‐803 cells. Changes in cell morphology, including disorganization of the architecture of actin microfilaments and formation of apoptotic bodies, together with cell cycle arrest in G2/M phases, were observed after treatment of plantamoside. The antiproliferative and pro‐apoptotic effects were associated with a decrease in the ratio of Bcl‐2/Bax and reduced mitochondrial membrane potential, which was accompanied by the release of reactive oxygen species and Ca2+ into the cytoplasm. Taken together, the results indicated that plantamoside promotes apoptosis via a mitochondria‐dependent mechanism. Copyright

Reinvestigation of the high spin states in 161Er and enhanced E1 transitions in the N = 93 isotones

High-spin states in 161Er have been studied experimentally using the 150Nd(16O, 5n) reaction at a beam energy of 86 MeV. The relatively enhanced E1 transitions between the 5/2+[642] and 3/2−[521] bands are observed in 161Er, and the B(E1) values are extracted experimentally. The systematics of the R(E1) values in the N = 93 isotones are presented. It is found that the strength of the E1 transitions obviously exhibits angular momentum dependence, and the occurrence of the relatively enhanced E1 transitions could be attributed to octupole softness.