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The article focuses on electric field control of magnon spin in an antiferromagnetic insulator. Topics icnlude the pure spin can be generated via thermal excitations of magnons, the magnon spin serve as carriers of information in insulating materials, and the demonstrate electric field control of magnon spin currents in the antiferromagnetic insulator Cr2O3.

Chlorinated persistent organic pollutants, including polychlorinated biphenyls (PCBs), represent a particularly serious environmental problem and human health risk worldwide. Leguminous plants and their symbiotic bacteria (rhizobia) are important components of the biogeochemical cycling of nitrogen in both agricultural and natural ecosystems. However, there have been relatively few detailed studies of the remediation of PCB-contaminated soils by legume-rhizobia symbionts. Here we report for the first time evidence of the reductive dechlorination of 2,4,4'-trichlorobiphenyl (PCB 28) by an alfalfa-rhizobium nitrogen fixing symbiont. Alfalfa (Medicago sativa L.) inoculated with wild-type Sinorhizobium meliloti had significantly larger biomass and PCB 28 accumulation than alfalfa inoculated with the nitrogenase negative mutant rhizobium SmY. Dechlorination products of PCB 28, 2,4'-dichlorobiphenyl (PCB 8), and the emission of chloride ion (Cl-) were also found to decrease significantly in the ineffective nodules infected by the mutant strain SmY. We therefore hypothesize that N2-fixation by the legume-rhizobium symbiont is coupled with the reductive dechlorination of PCBs within the nodules. The combination of these two processes is of great importance to the biogeochemical cycling and bioremediation of organochlorine pollutants in terrestrial ecosystems. [ABSTRACT FROM AUTHOR]

The contamination of soils by polycyclic aromatic hydrocarbons (PAHs) is a widespread environmental problem and the remediation of PAHs from these areas has been a major concern. The effectiveness of many in situ bioremediation systems may be constrained by low contaminant bioavailability due to limited aqueous solubility or a large magnitude of sorption. The objective of this research was to evaluate the effect of methyl-ß-cyclodextrin (MCD) on bioaugmentation by Paracoccus sp. strain HPD-2 of an aged PAH-contaminated soil. When 10% (W/W) MCD amendment was combined with bioaugmentation by the PAH-degrading bacterium Paracoccus sp. strain HPD-2, the percentage degradation of total PAHs was significantly enhanced up to 34.8%. Higher counts of culturable PAH-degrading bacteria and higher soil dehydrogenase and soil polyphenol oxidase activities were observed in 10% (W/W) MCD-assisted bioaugmentation soil. This MCD-assisted bioaugmentation strategy showed significant increases (p < 0.05) in the average well color development (AWCD) obtained by the BIOLOG Eco plate assay, Shannon-Weaver index (H) and Simpson index (k) compared with the controls, implying that this strategy at least partially restored the microbiological functioning of the PAH-contaminated soil. The results suggest that MCD-aided bioaugmentation by Paracoccus sp. strain HPD-2 may be a promising practical bioremediation strategy for aged PAH-contaminated soils. [ABSTRACT FROM AUTHOR]

Abstract: The dense ceramic part was prepared firstly using silazane with filler. The composition, structure and ceramic yield of silazane were characterized by elemental analysis, nuclear magnetic resonance (NMR), IR and thermogravimetric analysis (TGA). The ceramic yield was 63wt% upon pyrolysis at 1000°C under N2 atmosphere. The fabrication of ceramic part involved cross-linking of the silazane with metallic fillers (Ti particles) followed by a polymer-to-ceramic transformation step. Near net shape manufacturing of polymer derived ceramics could be achieved. The strength of ceramic parts could achieve 450±15MPa and scanning electron microscopy (SEM) observation showed that there was very low porosity on the fracture surface of pyrolysed body. [Copyright &y& Elsevier]

Abstract: Si–C–Ti ceramics were synthesized by reactive pyrolysis of polycarbosilane (PCS) precursor filled with metal Ti powder. Pyrolysis of mixture with atomic ratio of Ti:Si through 3:1–3:2 was carried out in argon atmosphere at given temperature up to 1500°C. The metal–precursor reactions, and phase evolution were studied using X-ray diffraction and scanning electron microscopy with EDX. The Ti3SiC2 phase was obtained firstly from reaction of PCS and Ti. Ti3SiC2 formation starts at 1300°C and its amount increases significantly in a narrow temperature range between 1400°C and 1500°C. In addition, addition of CaF2 can promote the formation of Ti3SiC2 phase. [Copyright &y& Elsevier]

From the aerial parts of Schisandra rubrifloraFranchRehd. et Wils., four new dibenzocyclooctadiene lignans, methylgomisin R 1, +14tigloylgomisin K32, 12demethylwuweilignan I 3, schisandrene A 4, together with 13known lignans, were isolated. The structures of four new compounds were elucidated by spectroscopic methods including extensive 1D and 2DNMR techniques. [ABSTRACT FROM AUTHOR]

Two-phase composites consisting of (1 - x) Al2O3 and xTi3SiC2 (x=0-1) were prepared by spark plasma sintering (SPS). Sintered densities larger than 98% of theoretical density were achieved when the specimens were sintered at 1300°C for 5 mm (in vacuum, at pressure 30 MPa). When content of Ti3SiC2 increased up to 30 wt%, composites were found to be machinable—they could be drilled easily using conventional Fe-Mo-W drills or gravers. The mechanical properties of the (1 - x) Al2O3-xTi3SiC2 composites were evaluated. The bending strength, Vickers hardness of the specimens had the following ranges: 428 ± 10.2 (x = 0) to 673 ± 15.4 Mpa (x = 1) (bending strength at room temperature); 19.9 (x = 0) to 4.0 GPa (x = 1) (Vickers hardness). [ABSTRACT FROM AUTHOR]

A functionally gradient material (FGM) of Al2O3–Ti3SiC2 was fabricated by spark plasma sintering (SPS) in vacuum. Its microstructure and properties were investigated. From examination of the dependence of the electrical conductivity on composition of the binary system Al2O3–Ti3SiC2, we determined the percolation threshold at which an interconnected network of electrically conductive phase arises. The hardness distribution across the entire composite was evaluated by Knoop indentation. The hardness was reduced with increasing content of Ti3SiC2. [Copyright &y& Elsevier]

Alumina/titanium silicon carbide (Al2O3–Ti3SiC2) composites and its functionally graded materials (FGMs) were fabricated by a powder metallurgy processes and their microstructure and properties were investigated, respectively. The experimental results showed that the Vickers hardness of composites decreased with increasing Ti3SiC2 content while the fracture toughness and strength exhibited the opposite trend. Minimum Vickers hardness (4 GPa), maximum strength (598 MPa) and maximum toughness (11.24 MPa m1/2) were reached in the pure Ti3SiC2 material. Strength and hardness of FGMs were evaluated. Observation using an scanning electron microscope (SEM) indicated that the presence of Ti3SiC2 of FGMs inhibited the growth of alumina grains through a pinning mechanism. The study shows that the combination of the layered Ti3SiC2 structure and the fine alumina grains can result in a Al2O3–Ti3SiC2 composites possessing a high toughness and low Vickers hardness without a sacrifice in the strength. [Copyright &y& Elsevier]

Abstract: Si3N4–TiN composite powders were obtained by in situ pyrolysis of polytitanosilazane. Dense Si3N4–TiN composites were prepared by hot-pressing at 1800°C under 20MPa for 2h without sintering additive. Crystallization of amorphous PTSZ powders occurred between 1400 and 1500°C with major phases, α-Si3N4, β-Si3N4, and small amount of phase TiN. Mechanical properties and microstructure of Si3N4–TiN composites were characterized. The results showed that the mechanical strength was 620MPa, the fracture toughness was 7.8MPam1/2 and the Vickers hardness was 8.5GPa. SEM analysis indicated that Si3N4–TiN composite possessed excellent fracture toughness because TiN grains produced by in situ pyrolysis were well dispersed in Si3N4 matrix. [Copyright &y& Elsevier]

Abstract: Titanium silicon carbide (Ti3SiC2) ceramic was synthesized by in-situ reaction of metal titanium and polycarbosilane. Reaction mechanisms which lead to the formation of Ti3SiC2 were suggested on the basis of XRD analysis. The content of Ti3SiC2 reached 93% in products obtained from heating the Ti/polycarbosilane green compact at 1400 °C in Ar. The morphology and compositions of the products were examined by SEM equipped with EDX. The typical laminate structure of Ti3SiC2 particles with 1–4 μm in thickness and 4–15 μm in length was observed. EDX results showed that the atomic ratio of Ti:Si:C of grains is close to 3:1:2, which agrees with Ti3SiC2 composition. [Copyright &y& Elsevier]

With mankind entering the smart age, Cd contamination risk control in food crop revolution has been put on the agenda. Based on the theoretical basis, technical methods and developing trends, this review look back and forward the age of Cd contamination risk control driven by 'genotype (G)+ envirotype (E)' dual-engines. Focusing on G, an inter-specific Cd contamination risk assessment meta-analysis was carried, in which a higher Cd contamination risk in rice and wheat than maize was observed. So different strategies are recommended to be taken considering inter-specific difference. To control the risk in crops with high accumulating characteristic, smart creation of low-Cd crops can be applied by two methods: 1) Excavating and pyramiding natural variations in natural population and 2) designing and implementing artificial variations which do not exist in natural population. Focusing on E, the influence of environmental factors to food crop Cd accumulation was discussed and the strategy using Envirotype-to-phenotype (E2P) models to predict and implement safety threshold were offered. In the foreseeable future, with the support of environmental science, biology, big data, artificial intelligence and other interdisciplinary and multi-technology, Cd contamination risk control will move toward intelligent, efficient and directional, ultimately realizing the revolutionary transformation from 'experience' to 'smart'. [ABSTRACT FROM AUTHOR]

Spin-flip probabilities from bulk defects and phonons are determined for the mesoscopic Cu channels of nonlocal spin valves (NLSVs). The NLSV spin signals are analyzed by a new approach to consistently extract the in situ values of the Cu spin diffusion length, effective spin injection (detection) polarization, and Cu resistivity. The size variations of the spin injectors (detectors) between NLSVs are treated by normalizing the spin signals to be commensurate with a standard injector (detector) size. The microstructure variations are statistically accounted for by measuring many NLSVs on the same substrate. From the Cu resistivity and spin diffusion lengths at 10 K and 295 K, the spin-flip probabilities from bulk defects and phonons are determined to be (3.9  ±  0.8)  ×  10−4 and (2.8  ±  1.2)  ×  10−4, respectively. [ABSTRACT FROM AUTHOR]

The article focuses on the role of Arabidopsis ABC transporter ABCB19 in exporting brassinosteroids, vital for plant growth and stress response. Topics discussed include ABCB19's ATPase activity stimulated by brassinosteroids, its binding affinities, transport mechanisms, structural analyses, and its positive regulation of brassinosteroid signaling alongside ABCB1, shedding light on molecular architecture and signaling cross-talk in plants.

Two new Chloratene F (1) and Chlomultin G (2), along with eight known sesquiterpenes (3-10) and six other known compounds (11-16) were isolated from the whole plant of Chloranthus henryi. Their structures were elucidated by HR-ESI-MS, NMR spectroscopic. The absolute configuration of two new compounds were determined by the X-ray crystallographic. All the compounds were reported for the first time from this species. [ABSTRACT FROM AUTHOR]

Accurate measurement of soil total N (TN) content in agricultural fields is important to guide reasonable application of nitrogenous fertilizer. Estimation of soil TN content with limited in situ data at an acceptable level of accuracy is important because laboratory measurement of N is a time-and labor-consuming procedure. This study was conducted to evaluate cokriging of soil TN with predicted soil organic matter (SOM) content as auxiliary data. The SOM content was predicted by cokriging with a digital number (DN) of Band 1 of Landsat Enhanced Thematic Mapper (ETM) imagery. Soil TN content was estimated by using 88 soil samples for prediction and 43 soil samples for validation in a study area of 367 km2 in Haining City, China. Field-measured soil TN content ranged from 0.47 to 2.48 g kg-1, with a mean of 1.25 g kg-1. Soil TN content of all 131 soil samples including samples for prediction and validation was highly correlated with measured (r = 0.81, p < 0.01) and predicted (r = 0.81, p < 0.01) SOM content in paddy fields. Then, the predicted SOM content was used as auxiliary variable for the prediction of soil TN content. By using the 43 samples for validation, we had a mean error (ME) of 0.03 g kg-1 and a root mean square error (RMSE) of 0.31 g kg-1 for kriging, and a mean error of 0.00 g kg-1 and a root mean square error of 0.25 g kg-1 for cokriging, respectively. Our results indicate cokriging with predicted SOM content data was superior to kriging. In addition, predicted data of the auxiliary variable have the potential to be useful for cokriging when the predicted auxiliary data have high prediction accuracy. [ABSTRACT FROM AUTHOR]

Accurately measuring soil organic matter content (SOM) in paddy fields is important because SOM is one of the key soil properties controlling nutrient budgets in agricultural production systems. Estimation of this soil property at an acceptable level of accuracy is important; especially in the case when SOM exhibits strong spatial dependence and its measurement is a time- and labor-consuming procedure. This study was conducted to evaluate and compare spatial estimation by kriging and cokriging with remotely sensed data to predict SOM using limited available data for a 367-km² study area in Haining City, Zhejiang Province, China. Measured SOM ranged from 5.7 to 40.4 g kg-1, with a mean of 19.5 g kg-1. Correlation analysis between the SOM content of 131 soil samples and the corresponding digital number (DN) of six bands (Band 1-5 and Band 7) of Landsat Enhanced Thematic Mapper (ETM) imagery showed that correlation between SOM and DN of Band 1 was the highest (r = -0.5 87). We used the DN of Band 1 as auxiliary data for the SOM prediction, and used descriptive statistics and the kriging standard deviation (STD) to compare the reliabilities of the predictions. We also used cross-validation to validate the SOM prediction. Results indicate that cokriging with remotely sensed data was superior to kriging in the case of limited available data and the moderately strong linear relationship between remotely sensed data and SOM content. Remotely sensed data such as Landsat ETM imagery have the potential as useful auxiliary variables for improving the precision and reliability of SOM prediction. [ABSTRACT FROM AUTHOR]

Organochlorine pesticides were used extensively in the Yangtze River Delta, China. However, knowledge about their residual levels and environmental fates in soils of this area is limited. This paper presents the residue isomers and spatial pattern of dichlorodiphenyltrichloroethane (DDT) in soils across 17 main cities in the Yangtze River Delta. Forty-three soil surface (0-15 cm) samples were collected during a field campaign conducted in October 2003 in the Delta. Six DDT isomers (1-[2-chlorophenyl]- 1-[4-chlorophenyl]-2,2-dichloroethane [o,p'-DDD], 1-[2-chlorophenyl]-1-[4-chlorophenyl]-2,2-dichloroethylene [o,p-'DDE], 1,1,1- trichloro-2-[p-chlorophenyl]-2-[o-chlorophenyl]ethane [o,p'-DDT], p,p'-dichlorodiphenyldichloroethane [p,p'-DDD], p,p'-dichlorodiphenyldichloroethylene [p,p'-DDE], p,p'-dichlorodiphenyltrichloroethane [p,p'-DDT]) were detected using gas chromatography. The results show that p,p'-DDE was the dominant isomer in the soil samples. The levels of DDT are generally low in soils of this area and are comparable to DDT levels in other cities in China and in soils from developed countries such as the United States and Germany. The isomer ratios of o,p'-DDT to p,p'-DDT and DDT to (DDD + DDE) were employed to identify the source of DDT. The computed ratios implied that the source of DDT might be related to the application of dicofol, an acaricide manufactured from technical DDTs and mainly used on cotton fields to treat mites. [ABSTRACT FROM AUTHOR]

Catalytic synthesis of di(methylphenyl)methane (CH3C6H4CH2C6H4CH3, DMPMs) from toluene and formaldehyde were investigated over various solids acids. At 140 °C and toluene/HCHO = 5/1, the conversion of HCHO over zeolite (Hβ, H-mordenite, HX, HY and HZSM-5) is limited, while heteropolyacids (H3PW12O40, H4SiW12O40 and H3PMo12O40) exhibited higher activity and DMPMs selectivity. The best yield of DMPMs reached 81.5% (conversion of HCHO nearly 100%). H3PW12O40 could be recovered by simply drying and the recycle-used catalyst remained its activity and structure in five runs. [ABSTRACT FROM AUTHOR]

A three-crop repeated phytoextraction experiment was conducted using four soils (S1-S4) highly polluted with cadmium (Cd) and two enhanced phytoextraction pot experiments using the most polluted soil (S4) to investigate the feasibility of Cd removal from highly polluted soils using the Cd/zinc (Zn)-hyperaccumulator Sedum plumbizincicola. Shoot biomass showed no significant difference during the repeated phytoextraction experiment on the four test soils and shoot Cd content showed a decreasing trend with the three consecutive crops in soils S1, S2, and S3 but not in soil S4. The Cd removal rates in soils S1, S2, S3, and S4 were 84.5, 81.6, 45.3, and 32.4%, respectively. Rice straw application increased Cd extraction efficiency by 42.6% but the addition of ethylenediaminedisuccinic acid, biochar or nitrogen had no effect on Cd remediation. Shoot Cd content increased significantly (1.57 and 1.71 times, respectively) at low (S0-1) and high (S0-2) sulfur addition rates. Soil extractable-Cd in S0-1 after the experiment showed no significant difference from the control but was 2.43 times higher in S0-2 than in the control. These results indicate that S. plumbizincicola shows good prospects for the phytoextraction of Cd from highly polluted soils and that the process can be enhanced by adding straw and/or sulfur to the soil. [ABSTRACT FROM AUTHOR]

The low temperature process of cold dew wind (from September 19 to 27 in 2011) for late rice production was dynamically monitored by using CLDAS temperature, combined with the background information of rice cultivation from multi-source satellite database together with an reference to the monitoring indexes of cold dew wind disaster to verify the precision of CLDAS data, so as to provide a reference for monitoring chilling damage caused by cold dew wind in late rice production in Guangxi. The results showed that the cold wind dew caused heavy damage to an area of 3 159.76 km², moderate damage to an area of 559.77 km² and light damage to an area of 2 452.14 km². The correlation coefficients between CLDAS inversion temperature and actual temperature of 12 verification meteorological stations were all larger than 0.93, and the difference in daily average temperature was 0.3 °C. The time difference between maximum and minimum temperature provided by CLDAS and corresponding actual temperature from 12 meteorological stations was less than 1 h. The temperature data provided by CLDAS wa in accordance with actual temperature data. With an advantage of rapidly, minutely and accurately monitoring the grade distribution of local cold dew wind disaster for late rice, CLDAS can be used in monitoring cold dew wind in late rice production in Guangxi. [ABSTRACT FROM AUTHOR]

Legume-rhizobium symbioses have the potential to remediate soils contaminated with chlorinated organic compounds. Here, the model symbiosis between Medicago sativa and Sinorhizobium meliloti was used to explore the relationships between symbiotic nitrogen fixation and transformation of tetrachlorobiphenyl PCB 77 within this association. 45-day-old seedlings in vermiculite were pretreated with 5 mg L-1 PCB 77 for 5 days. In PCB-supplemented nodules, addition of the nitrogenase enhancer molybdate significantly stimulated dechlorination by 7.2-fold and reduced tissue accumulation of PCB 77 (roots by 96% and nodules by 93%). Conversely, dechlorination decreased in plants exposed to a nitrogenase inhibitor (nitrate) or harboring nitrogenase-deficient symbionts (nifA mutant) by 29% and 72%, respectively. A range of dechlorinated products (biphenyl, methylbiphenyls, hydroxylbiphenyls, and trichlorobiphenyl derivatives) were detected within nodules and roots under nitrogen-fixing conditions. Levels of nitrogenase-derived hydrogen and leghemoglobin expression correlated positively with nodular dechlorination rates, suggesting a more reducing environment promotes PCB dechlorination. Our findings demonstrate for the first time that symbiotic nitrogen fixation acts as a driving force for tetrachlorobiphenyl dechlorination. In turn, this opens new possibilities for using rhizobia to enhance phytoremediation of halogenated organic compounds. [ABSTRACT FROM AUTHOR]

Contaminant arsenic(V) has been regarded as one of the top-priority pollutants to remove from water. In this contribution, different mesoporous Y-Al binary oxides were prepared by the wet impregnation method via varying the molar ratio of Y/Al in the range of 0.029 to 0.116. The manufactured materials were employed as adsorbent to separate arsenic(V) from water. The adsorbent was characterized by N2 adsorption--desorption isotherm, point of zero charge (PZC) and Fourier transform infrared (FT-IR). Furthermore, the effect of experimental parameters on adsorption performance was evaluated by batch experiments, including the molar ratio of Y/Al, adsorbent dosages and contact time, initial concentration, initial pH and temperature. The results indicated that the adsorbent presented an optimal adsorption performance for As(V) uptake when the molar ratio of Y/Al was 0.058. The obtained experimental data were best fitted by Langmuir isotherm and the maximum adsorption capacity was 60.93 mg/g at pH 6.6 ±0.1. Additionally, according to the results of adsorption kinetics, it was pronounced that adsorption process was complied with pseudo-second-order model. The adsorption thermodynamic suggested that the adsorption of As(V) is endothermic and spontaneous natural. Moreover, based on the results of FT-IR, PZC and initial pH, it is demonstrated that ion-exchange and electrostatic interaction were the dominating adsorption mechanism. [ABSTRACT FROM AUTHOR]

A novel urea grind combustion (UGC) route was reported in this paper to rapidly prepare the ceria-zirconia nanoparticles (Ce0.8Zr0.2O2). For comparison, the conventional surfactant-assisted (SA) and sol-gel (SG) methods were also employed to prepare Ce0.8Zr0.2O2 nanoparticles. CO preferential oxidation in H2-rich stream (CO-PROX) was chosen as probe reaction to investigate the catalytic performance of these Ce0.8Zr0.2O2 catalysts prepared with different methods to highlight the superiority of UGC. It was found that Ce0.8Zr0.2O2-UGC showed the better reducibility and oxygen mobility than the Ce0.8Zr0.2O2 prepared by SA and SG, because the UGC route favored the more incorporation of zirconia into CeO2, leading to more serious distortion of the structure, and more defective sites in the Ce0.8Zr0.2O2. As a result, Ce0.8Zr0.2O2-UGC exhibited the higher CO conversion, better O2 selectivity, and excellent catalytic stability without any deactivation during 72-h reaction on stream. More importantly, the UGC method, as compared to the relatively complex and time-consuming SA and SG method, is simple, facile, low-cost, time-saving (within 30 minutes) and scalable, thereby, might be very promising for the application in many fields. [ABSTRACT FROM AUTHOR]

The photolysis of tetrabromobisphenol A (TBBPA) in aqueous solution under simulated solar light irradiation was studied under different conditions to find out mechanisms and pathways that control the transformation of TBBPA during photoreaction. Particular attention was paid to the identification of intermediates and elucidation of the photolysis mechanism of TBBPA by UPLC, LC/MS, FT-ICR-MS, NMR, ESR, and stable isotope techniques (13C and 18O). The results showed that the photolysis of TBBPA could occur under simulated solar light irradiation in both aerated and deaerated conditions. A magnetic isotope effect (MIE)-hydrolysis transformation was proposed as the predominant pathway for TBBPA photolysis in both cases. 2,6-Dibromophenol and two isopropylphenol derivatives were identified as photooxidation products of TBBPA by singlet oxygen. Reductive debromination products tribromobisphenol A and dibromobisphenol A were also observed. This is the first report of a photolysis pathway involving the formation of hydroxyl-tribromobisphenol A. [ABSTRACT FROM AUTHOR]

Ag speciation in a chloride medium was dependent upon the Cl/Ag ratio after releasing into surface water. In this study, the photoreaction of in situ formed Ag-Cl species and their effects on aniline photochlorination were systematically investigated. Our results suggested that formation of chloroaniline was strongly relevant to the Cl/Ag ratio and could be interpreted using the thermodynamically expected speciation of Ag in the presence of Cl-. AgCI was the main species responsible for the photochlorination of aniline. Both photoinduced hole and •OH drove the oxidation of Cl- to radical •Cl, which promoted the chlorination of aniline. Ag0 formation was observed from the surface plasmon resonance absorption during AgCI photoreaction. This study revealed that Ag+ released into Cl--containing water may result in the formation of chlorinated intermediates of organic compounds under solar light irradiation. [ABSTRACT FROM AUTHOR]

The SBA-15 (a mesoporous SiO2material) decorated with10% aluminum (Al10-SBA-15) was found to be an excellentadsorbent to remove As(V) from water. The highly dispersed aluminumspecies have been obtained over the well-ordered mesoporous Al10-SBA-15 adsorbent and act as the active adsorption sitesfor arsenic(V) removal instead of SiO2. The adsorptionbehavior of As(V) onto Al10-SBA-15 was investigated inaqueous solution using various experimental parameters. The adsorptiondata of As(V) could be fitted more successfully by the Langmuir isothermthan the Freundlich isotherm model, and the pseudo-second-order equationdescribed this entire adsorption process well. It is found from theanalysis of kinetic data with the intraparticle diffusion mode thatboth the boundary layer (film) diffusion and intraparticle diffusionmay contribute to the rate-limiting steps. Importantly, Al10-SBA-15 exhibits high arsenic(V) removal in the wide pH range of2.0–8.2 and can remove As(V) from water containing arsenateof ≤2.235 mg·L–1to reach levels inaccordance with the regulations for drinking water purposes (<10μg·L–1). Consequently, Al10-SBA-15 is believed to be an effective adsorbent for treating arsenatecontaminated wastewater. [ABSTRACT FROM AUTHOR]

Pot and field experiments were conducted to investigate the effects of water regimes on the speciation and accumulation of arsenic (As) and cadmium (Cd) in Brazilian upland rice growing in soils polluted with both As and Cd. In the pot experiment constant and intermittent flooding treatments gave 3-16 times higher As concentrations in soil solution than did aerobic conditions but Cd showed the opposite trend. Compared to arsenate, there were more marked changes in the arsenite concentrations in the soil solution as water management shifted, and therefore arsenite concentrations dominated the As speciation and bioavailability in the soil. In the field experiment As concentrations in the rice grains increased from 0.14 to 0.21 mg/kg while Cd concentrations decreased from 0.21 to 0.02 mg/kg with increasing irrigation ranging from aerobic to constantly flooding conditions. Among the various water regimes the conventional irrigation treatment produced the highest rice grain yield of 6.29 tons/ha. The As speciation analysis reveals that the accumulation of dimethylarsinic acid (from 11.3% to 61.7%) made a greater contribution to the increase in total As in brown rice in the intermittent and constant flooding treatments compared to the intermittent-aerobic treatment. Thus, water management exerted opposite effects on Cd and As speciation and bioavailability in the soil and consequently on their accumulation in the upland rice. Special care is required when irrigation regime methods are employed to mitigate the accumulation of metal(loid)s in the grain of rice grown in soils polluted with both As and Cd. [ABSTRACT FROM AUTHOR]

Amino-functionalized mesoporous silica MCM-41 materials have been prepared to develop efficient adsorbents of Cr(VI) in wastewater, using silica fume as silica source. Functionalization with amino groups has been carried out by using grafting method. The materials have been characterized by means of X-ray diffraction (XRD), nitrogen (N2) adsorption-desorption, Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), transmission electron microscopy (TEM), and X-ray photoelectron spectroscopy (XPS). Adsorption potential of the material for Cr(VI) removal from aqueous solution was investigated by varying experimental conditions such as pH, initial metal concentration, and contact time. The equilibrium data were analyzed using the Langmuir and Freundlich isotherm by linear regression analysis, and the results show that the adsorption equilibrium data obeyed the Langmuir model. In addition, the kinetics analysis revealed that the overall adsorption process was successfully fitted with the pseudo-second-order kinetic model. [ABSTRACT FROM AUTHOR]

Phytoextraction has become one of the most promising remediation techniques for heavy metal (HM) contaminated soils. However, the technique invariably produces large amounts of HM-enriched hyperaccumulators, which need further safe disposal. In this study, two different thermal treatment methods are investigated as potential options for evaporative separation of HMs from the residues. A horizontal tube furnace and a vertical entrained flow tube furnace were used for testing the disposal of grounded hyperaccumulators. The release characteristics of HMs (Cd, Cu, Pb, and Zn) into flue gas and residues were investigated for thermal treatment of the Cd and Zn hyperaccumulators Sedum plumbizincicola and Sedum alfredii. In a horizontal tube furnace, incineration favors the volatilization of Cu and Cd in contrast to pyrolysis. The percentages of HMs in residues after incineration are lower than those after pyrolysis, especially for Cd, Pb, and Zn. However, in an entrained flow tube furnace, Zn content in flue gas increases with increasing temperature, but Cu and Cd contents are fluctuated. In addition, a higher incineration temperature enhances the Cu content in residues. [ABSTRACT FROM AUTHOR]

new liquid polyborosilazane precursor for Si-B-C-N ceramic was synthesized by co-condensation reaction of boron trichloride, organodichlorosilanes, and hexamethyldisilazane. The structure and properties of polyborosilazane were studied by means of Fourier transform-infrared spectroscopy (FT-IR), nuclear magnetic resonance (NMR), rheology, and thermogravimetric analysis (TGA). The conversion of polymer to ceramic and the high-temperature behavior of the new polymer-derived ceramic were investigated by TG-MS, FT-IR, X-ray diffraction (XRD) and high-temperature TGA (HTGA). The ceramics showed good oxidative resistance and thermal stability with weight gain of 1.8 wt% at 1350 °C under air atmosphere and weight loss of 2.6% at 1900 °C under Ar atmosphere. [ABSTRACT FROM AUTHOR]

Background: LGD1069 (Targretin®) is a selective retinoid X receptor (RXR) ligand, which is used in patients for cutaneous T-cell lymphoma. Our published study reported that LGD1069 inhibited tumor-induced angiogenesis in non-small cell lung cancer. In present study, we found that LGD1069 suppressed the proliferation, adhesion, invasion and migration of endothelial cells directly, and affected the expression of vegf and some matrix genes. Methods: Human umbilical vein endothelial cells (HUVECs) were used for in vitro study. MTT assay and Sulforhodamine B assay were used for cell viability assay; the tube formation assay was used to investigate the effect of LGD1069 on angiogenesis in vitro. In vitro adhesion, migration and invasion of HUVEC cells were analyzed by Matrigel adhesion, migration and invasion assay. Gene expressions were measured by RT-PCR and Western blot analysis. Results: Our data showed here that LGD1069 inhibited the activation of TGF-β/Smad pathway significantly. Furthermore, it was demonstrated that expression of Runx2 was suppressed pronouncedly during incubation with LGD1069. Runx2 is a DNA-binding transcription factor which plays a master role in tumor-induced angiogenesis and cancer cells metastasis by interaction with the TGF-β/Smad pathway of transcriptional modulators. Conclusions: Our results suggested that LGD1069 may impair angiogenic and metastatic potential induced by tumor cells through suppressing expression of Runx2 directly on human endothelial cells, which may point out new pathway through which LGD1069 display anti-angiogenic properties, and provide new molecular evidence to support LGD1069 as a potent anti-metastatic agent in cancer therapy. [ABSTRACT FROM AUTHOR]

The use of the [S,S]-isomer of EDDS to enhance phytoextraction has been proposed for the remediation of heavy metal contaminated soils. Speciation of metals in soil solution in the presence of EDDS and dissolved organic matter (DOM) received, however, almost no attention, whereas metal speciation plays an important role in relation to uptake of metals by plants. We investigated the influence of EDDS on speciation of dissolved metals in batch extraction experiments using fourfield-contaminated soils with pH varying between 4.7 and 7.2. Free metal concentrations were determined with the Donnan membrane technique, and compared with results obtained with the chemical speciation program ECOSAT and the NICA-Donnan model using a multi-component approach. Addition of EODS increased total metal concentrations in our soil extracts by a factor between 1.1 and 32 (AI), 2.1-48 (Cu), 1.1-109 (Fe), 1.1-5.5 (Ni), and 1.3-17 (Zn). In general, Al, Cu, Fe, and Zn had the largest total concentrations in the EDDS-treated extracts, but the contribution of these metals to the sum of total metal concentrations varied significantly between our soils. Free metal concentrations varied between 7.0 and 8.9 (pCd2+, 3.9-9.9 (pCu2+), 6.3-10.2 (pNi2+), and 5.2-7.0 (pZn2+). Addition of EDDS decreased free metal concentrations by a factor between 1.4 and 1.9 (Cd), 3.4-216 (Cu), 1.3-186 (Ni), and 1.3-3.3 (Zn). Model predictions of free metal concentrations were very good, and predicted values were mostly within 1 order of magnitude difference from the measured concentrations. A multicomponent approach had to be used in our model calculations, because competition between Fe and other metals for binding with EDDS was important. This was done by including the solubility of metal oxides in our model calculations. Multicomponent models can be used in chelant-assisted phytoextraction experiments to predict the speciation of dissolved metals and to increase the understanding of metal uptake by plants. [ABSTRACT FROM AUTHOR]

Abstract: A pot experiment was conducted to examine the roles of indigenous and non-indigenous arbuscular mycorrhizal (AM) fungi in As uptake by maize (Zea mays L.) from original As-polluteded soil, and their effects on As and P fractions in the rhizosphere. The As-polluted soils with three As levels, were collected from As-polluted arable soil near an As mine. Indigenous AM fungi (M2: including Glomus spp., Acaulospora spp.) isolated from these soils were compared with a non-indigenous AM fungus (M1: Glomus caledonium 90036). The plants were harvested after 10 weeks of growth. Mycorrhizal colonization rate, dry weight (DW) and P, As concentrations in plants, as well as As and P fractions, were determined. Compared to the non-mycorrhizal treatment, at the high soil As level, maize inoculated with AM fungi had higher shoot and root DW and P contents, both M1 and M2 inoculations increased As accumulation in root, though M1 reduced shoot As content, and M2 transported more As from roots to shoots. M1 decreased root and shoot As contents at the low and medium soil As levels. Plants mainly took up non-specifically sorbed As at the high soil As level, but As was taken up from hydrous oxides of Fe and Al at the low and medium soil As levels. All results indicate that indigenous consortia M2 could protect their host plants from the toxicity of excessive As through P nutrition by activating P, though non-indigenous M1 could alleviate As toxicity through stabilizing As and P in the soil. [Copyright &y& Elsevier]

The protective effects of sasanquasaponin, an effective compound from Chinese traditional herbs, on ischaemia and reperfusion injury in mouse hearts have been suggested through modulation of intracellular Cl− homeostasis. The effects of sasanquasaponin on injury of endothelial cells, however, induced by anoxia and reoxygenation remain unknown. Therefore, the present study attempted to observe the effects of sasanquasaponin on anoxia and reoxygenation injury in endothelial cells and investigate its putative mechanisms. Human umbilical vein endothelial cells (HUVECs) were exposed to normoxia or anoxia and reoxygenation in the absence or presence of sasanquasaponin (10.0, 1.0 and 0.1 µmol/l). Lactate dehydrogenase activity was determined in cultured HUVECs supernatant, and malondialdehyde content, superoxide dismutase and glutathione peroxidase activities were measured in HUVECs by a colorimetric method. Neutrophil adhesion to HUVECs was assayed colorimetrically. The levels of intercellular adhesion molecule-1 and tumour necrosis factor-α were detected. The activity of nuclear factor kappa B was determined by flow cytometry. The results show that sasanquasaponin decreased the lactate dehydrogenase activity and malondialdehyde contents, and inhibited the neutrophil adhesion to HUVECs; sasanquasaponin, moreover, inhibited nuclear factor kappa B transnuclear activity, lowered tumour necrosis factor-α and intercellular adhesion molecule-1 expression levels. On the other hand, sasanquasaponin increased the mitochondrial superoxide dismutase and glutathione peroxidase activities. It is suggested that sasanquasaponin could protect HUVECs against anoxia and reoxygenation injury, and the protective mechanisms appear to be related to anti-lipoperoxidation and anti-adhesion. [ABSTRACT FROM AUTHOR]

A comparison of structure and pattern of the soil seed bank was made between active and stabilized sand dunes in northeastern Inner Mongolia, China. The objective of this paper was to determine the significance of seed bank in vegetation restoration of sand dunes. The results showed that (1) average seed density decreased from stabilized sand dune to interdune lowland of stabilized sand dune, to interdune lowland of active sand dune, and to active sand dune; (2) horizontally, along the transect from interdune lowland to ecotone and to sand dune top, a ‘V’ shaped pattern was presented in the active dune system, and a reverse ‘V’ shaped pattern in the stabilized sand dune system; (3) vertically, the proportion (accounting for the total seeds) of seeds found in 0–20 mm soil profile decreased from stabilized sand dune to interdune lowland of stabilized sand dune, to interdune lowland of active sand dune, and to active sand dune. The same order was also found in 20–50 mm and 50–100 mm soil profiles; (4) the Sokal and Sneath similarity indices in the species-composition between soil seed bank and above-ground vegetation were ranked as: the stabilized sand dune (24%) > the interdune lowland of active sand dune (21%) > the interdune lowland of stabilized sand dune (18%) > the active sand dune (5%); and (5) vegetation restoration of active sand dunes depends on the dispersal of seeds from nearby plant communities on the interdune lowlands. Much effort must be made to preserve the lowlands, as lowlands are the most important seed reservoir in the active sand dune field. [ABSTRACT FROM AUTHOR]

Lanthanum phosphate powders were synthesized by direct solid–liquid reaction of lanthanum oxide and phosphoric acid at the La:P ratio of 1:1. Phase-pure and fine grain size LaPO4 powders could be obtained by calcining the as-received powders at the temperature higher than 600 °C. It was demonstrated that the phase type, grain size and morphology of the LaPO4 powders were calcined at various temperatures. We have studied the microstructure of sintered LaPO4 ceramic and Al2O3/LaPO4 composite using the synthesized powders by SEM and TEM analysis. An interesting layered crystal structure and lots of dislocations inside LaPO4 grains and at the interface of Al2O3/LaPO4 composite were observed. Low hardness and multiple dislocations and dislocation networks indicated the layered LaPO4 ceramic could possess excellent machinability. As an example for engineering application, machinable Al2O3/LaPO4 composite with weak bonding was fabricated and characterized. [Copyright &y& Elsevier]

A new design method of machinable ceramic composites was proposed, which applies the graded-structure concept to the design of machinable Si3N4 ceramics. Silicon nitride/hexagonal boron nitride (h-BN) ceramic composites and functionally graded materials were fabricated by hot pressing at 1750 °C for 2 h, varying the alignment of the amount of hexagonal BN using powder layering method. The improved machinability of Si3N4/h-BN composite can be attributed to addition of layered structure hexagonal BN. Hexagonal BN possesses excellent cleavage planes perpendicular to the c-axis. Ease of machining depends on degree of crystal interlocking; hence volume content of h-BN crystals and their aspect ratio affect machinability. The texture of h-BN and β-Si3N4 was observed during hot pressing sintering. Physical and mechanical properties of Si3N4/h-BN with different content of h-BN were investigated, such as bulk density, Vickers''s hardness, flexural strength, and elastic modulus. All of these properties are important for the design of the machinable Si3N4/h-BN FGM (Functionally Graded Materials). [Copyright &y& Elsevier]

The energy efficiency of the spin Hall effects (SHE) can be enhanced if the electrical conductivity is decreased without sacrificing the spin Hall conductivity. The resistivity of Pt films can be increased to 150–300 µΩ · cm by mesoscopic lateral confinement, thereby decreasing the conductivity. The SHE and inverse spin Hall effects (ISHE) in these mesoscopic Pt films are explored at 10 K by using the nonlocal spin injection/detection method. All relevant physical quantities are determined in situ on the same substrate, and a quantitative approach is developed to characterize all processes effectively. Extensive measurements with various Pt thickness values reveal an upper limit for the Pt spin diffusion length:   ⩽  0.8 nm. The average product of and the Pt spin Hall angle is substantial:   =  (0.142  ±  0.040) nm for 4 nm thick Pt, though a gradual decrease is observed at larger Pt thickness. The results suggest enhanced spin Hall effects in resistive mesoscopic Pt films. [ABSTRACT FROM AUTHOR]